I decided I was going to jump into the simulator market a couple weeks ago and did as much homework as I could prior to making any purchases.
Obviously budget is the biggest issue when looking at what to buy as there seem to be more "lower-end" (ex. optishot) and "higher-end" (ex. trackman) devices but not too many in that middle range. From everything I could find, the Skytrak and GC2 systems are basically the closest you're going to get to the Trackman, Flightscope range and stay under 5k (for the launch monitor alone).
With more funding, I probably would have picked up a GC2, but I decided to go with the Skytrak in an effort to get started sooner rather than later as i'd have to save up quite a bit more $$ to go the GC2 route.
I ended up with the Skytrak unit with protective case (from Skytrak site), 9x10 Beta-SQ impact screen (from Par2Pro) and the Country Club Elite hitting mat (Costco, oddly enough). Additionally I bought a new gaming laptop (Newegg via Ebay) and an Optoma GT1080darbee projector (also Newegg via Ebay) #coupons. The simulator SW I chose was Jack Nicklaus Perfect Golf.
After everything arrived, I've now played two full rounds and can say that I've enjoyed it thus far. The weather here in MD hasn't been ideal, as spring has yet to show itself for more than a day, so being able to play as much as I want in the garage has been great.
The things I've noticed are:
1) The Skytrak was super easy to setup and get started.
2) The distances I was seeing on the Skytrak driving range were relatively accurate for me.
3) The JPNG simulation software is aesthetically awesome. They've done a great job w/ the courses.
4) What I'm finding thus far is that the distance translation from the Skytrak to the JPNG simulation software isn't as accurate as the Skytrak range. I find myself coming up short on most shots outside of 150y. I've decided I'm going to toy with this more - it could be how I have the Skytrak positioned (on the floor and raised to mat level).
5) Happy thus far w/ the screen (it's a "beta" version that Par2Pro has just released, so there are no durability stats yet, but the picture and impact sound are very good)
6) The projector is excellent also - the picture is great.
As things progress and my trial-and-error continues, I'll hopefully be able to provide more info as well as some pictures.
Hope this is helpful.