ancient city

Each of the models are different; sometimes really subtle differences, but differences nonetheless.
From what I read on the interweb, your speeder is a fairly high launch shaft.  So if you are launching it higher than you want, then a change might be in order.  But without time with a launch monitor and testing different shafts, changing shafts to any brand/model would be a roll of the dice.  I couldn't begin to guess what kind of results you'd get from the HD.  
Have you hit your friend's driver?  Have you been to a store where you can hit some different shafts?  Perhaps get an idea if a shaft with a higher bend point yields a more desirable ball flight?  Or is the PXG an inherently higher launching head?  Too many unknowns...

tons of rain here lately but slogged through a round to finally put the HD in play...10 of 13 fairways; no penalties; no big pulls.  It is a very good fit for me; I'm impressed.

tons of rain here lately but slogged through a round to finally put the HD in play...10 of 13 fairways; no penalties; no big pulls.  It is a very good fit for me; I'm impressed.

Finally got the HD out on the range and the results mirrored the trackman results from the fitting...maybe got a couple more yards carry (I never hit the ball in a simulator as well as I do live...I think it's the squishy footing on the mats).  I'll say this, I don't think it's a shaft that allows for much workability left and right; but that can be a bonus for consistency.  Want a very repeatable result?  This will do it.

Finally got the HD out on the range and the results mirrored the trackman results from the fitting...maybe got a couple more yards carry (I never hit the ball in a simulator as well as I do live...I think it's the squishy footing on the mats).  I'll say this, I don't think it's a shaft that allows for much workability left and right; but that can be a bonus for consistency.  Want a very repeatable result?  This will do it.

Finally got the HD out on the range and the results mirrored the trackman results from the fitting...maybe got a couple more yards carry (I never hit the ball in a simulator as well as I do live...I think it's the squishy footing on the mats).  I'll say this, I don't think it's a shaft that allows for much workability left and right; but that can be a bonus for consistency.  Want a very repeatable result?  This will do it.

I spoke to the HD shaft (6S) at the beginning of this thread.  I've been tinkering with the driver set up.  My previous driver shaft was the Mitsubishi AV white played at 11 degrees (Callaway Rogue LS).  I was looking for an improved dispersion pattern.  Long story short - I'm down to 8 degrees in a draw setting.  Once Callaway TD goes past model, I'll pick up a head in 8 degrees.  Just came back from a round where I had 5 personal long drives on my home course.  I'm 65 years young and still playing the white tees (6700 yards).  I'm a little bit longer than you but not by much.  My 150-yard club is an 8 iron.    My drives are getting more consistent and longer.  
I've hit virtually every GD shaft.  Their description is dead on.  IMO all their shafts are all smooth.  It just depends on what matches your swing. Much smoother than the Ventus line. I had the Ventus Black in 6S and tried the Ventus Blue in 6S.   My experience was the same as yours.  Similar distance worse dispersion.  Every time I make a bad swing with the GD shaft I can feel it.  Only other GD shaft I liked was the TP, but the HD was smoother in feel.  The new GC looks interesting as 4, 3, 3+.  Might be too stiff in the handle.   
BTW - I picked up the HD in 6S in a fairway shaft for the Ping G430 3 wood.  Have it set up at 14 degrees flat. Not the longest 3 wood in the bag.  But I'll take 225 down the middle every time. 
What I've found with the GD shafts in general is that they are underrated for sure.  Second - it takes time to find that Goldilocks setup.  Once you find it their description of "Accuracy and Distance" is not a fib.
 
 
 

yes, very much so.  
The optimizer on Trackman showed what I already knew, that if I increase loft a couple of degrees, I'd get 10 yds+ more carry.  But with a slow swing speed, I'd be eaten alive hitting into the wind so I tend toward max rollout.  And I don't hesitate to adjust loft if I need to prior to a round.  If it's 85% humidity and dead calm, or if the course is really soft, I'll bump the loft up a click and tee the ball up a tad more.
  
 
 

No one tested the HD?
Just did a shaft retrofit at Club Champion and the HD was the clear winner.  HD has Graphite Design's 3-3-3+ profile.
I'm a 69 year old with an 85 mph driver swing speed.  Since we often have a decent breeze blowing here in St Augustine, FL.  I prefer a fairly low ball flight and typically play a slight fade.  I'd like to call it a "power fade" but I don't really have any power, lol.   My carry distance is between 190-200 yds with a roll out to 210-225.  Don't currently have a HCP index (back in the day I was a +6) but I average +9 at 6000 yards (sea level).  If I move up to the senior tees I'm about 3 strokes better. 
I'm pretty accurate and consistent with my irons and fairway woods and have a competent short game.  When I'm in the fairway off the tee, I'll shoot in the mid to low 70's.  I've shot level par for 9 holes a few times; hence the search for accuracy off the tee.
Swing speed suggests I should play a regular flex but I have a quick transition and get much better performance from a stiff flex, especially in the driver and 3 wood.  Currently have a stock Speeder NX (stiff) in a Qi 10 LS.  Loft setting is either 7.0 or 7.5 degrees.  I get acceptable distance (for me) but I've been spraying it all over the place.  Went to CC looking for the least dispersion I could get without sacrificing distance.
After working through maybe 10 different shafts, the fitting came down to Ventus Blue (velocore) and the AD HD (both in 5 stiff).  Distance was the same.  But the HD was much more consistent and had half the dispersion...ALL of the shots with the HD were closer to the center line than than the best with the Ventus. 
Speeder is purple, Ventus is red, and AD HD is blue in the image below.  Driver loft was 7.0 on those graphics but I will likely play the HD at 7.5 or 8.25, depending on course conditions. 
Looking forward to delivery!
 
 

No one tested the HD?
Just did a shaft retrofit at Club Champion and the HD was the clear winner.  HD has Graphite Design's 3-3-3+ profile.
I'm a 69 year old with an 85 mph driver swing speed.  Since we often have a decent breeze blowing here in St Augustine, FL.  I prefer a fairly low ball flight and typically play a slight fade.  I'd like to call it a "power fade" but I don't really have any power, lol.   My carry distance is between 190-200 yds with a roll out to 210-225.  Don't currently have a HCP index (back in the day I was a +6) but I average +9 at 6000 yards (sea level).  If I move up to the senior tees I'm about 3 strokes better. 
I'm pretty accurate and consistent with my irons and fairway woods and have a competent short game.  When I'm in the fairway off the tee, I'll shoot in the mid to low 70's.  I've shot level par for 9 holes a few times; hence the search for accuracy off the tee.
Swing speed suggests I should play a regular flex but I have a quick transition and get much better performance from a stiff flex, especially in the driver and 3 wood.  Currently have a stock Speeder NX (stiff) in a Qi 10 LS.  Loft setting is either 7.0 or 7.5 degrees.  I get acceptable distance (for me) but I've been spraying it all over the place.  Went to CC looking for the least dispersion I could get without sacrificing distance.
After working through maybe 10 different shafts, the fitting came down to Ventus Blue (velocore) and the AD HD (both in 5 stiff).  Distance was the same.  But the HD was much more consistent and had half the dispersion...ALL of the shots with the HD were closer to the center line than than the best with the Ventus. 
Speeder is purple, Ventus is red, and AD HD is blue in the image below.  Driver loft was 7.0 on those graphics but I will likely play the HD at 7.5 or 8.25, depending on course conditions. 
Looking forward to delivery!
 
 

yes, very much so.  
The optimizer on Trackman showed what I already knew, that if I increase loft a couple of degrees, I'd get 10 yds+ more carry.  But with a slow swing speed, I'd be eaten alive hitting into the wind so I tend toward max rollout.  And I don't hesitate to adjust loft if I need to prior to a round.  If it's 85% humidity and dead calm, or if the course is really soft, I'll bump the loft up a click and tee the ball up a tad more.
  
 
 

No one tested the HD?
Just did a shaft retrofit at Club Champion and the HD was the clear winner.  HD has Graphite Design's 3-3-3+ profile.
I'm a 69 year old with an 85 mph driver swing speed.  Since we often have a decent breeze blowing here in St Augustine, FL.  I prefer a fairly low ball flight and typically play a slight fade.  I'd like to call it a "power fade" but I don't really have any power, lol.   My carry distance is between 190-200 yds with a roll out to 210-225.  Don't currently have a HCP index (back in the day I was a +6) but I average +9 at 6000 yards (sea level).  If I move up to the senior tees I'm about 3 strokes better. 
I'm pretty accurate and consistent with my irons and fairway woods and have a competent short game.  When I'm in the fairway off the tee, I'll shoot in the mid to low 70's.  I've shot level par for 9 holes a few times; hence the search for accuracy off the tee.
Swing speed suggests I should play a regular flex but I have a quick transition and get much better performance from a stiff flex, especially in the driver and 3 wood.  Currently have a stock Speeder NX (stiff) in a Qi 10 LS.  Loft setting is either 7.0 or 7.5 degrees.  I get acceptable distance (for me) but I've been spraying it all over the place.  Went to CC looking for the least dispersion I could get without sacrificing distance.
After working through maybe 10 different shafts, the fitting came down to Ventus Blue (velocore) and the AD HD (both in 5 stiff).  Distance was the same.  But the HD was much more consistent and had half the dispersion...ALL of the shots with the HD were closer to the center line than than the best with the Ventus. 
Speeder is purple, Ventus is red, and AD HD is blue in the image below.  Driver loft was 7.0 on those graphics but I will likely play the HD at 7.5 or 8.25, depending on course conditions. 
Looking forward to delivery!