I have been playing Krank drivers for about 10 years now. I am currently 58 years old, and swing speed is usually 108 to 112. I am putting the ball between 290 and 310 consistently with the previous generation Krank driver, not the current Fire driver. I have hit other drivers from Ping and Calloway and have liked the clubs, but I feel the Krank has been most consistently long even with off center hits. They have had great customer service, so I have stayed with them so far.
It is also fun when pulling it out of the bag and other golfers ask what is that? Lol then proceed to roll the ball past them in the fairway. If I were buying today, I would probably do the new 10k drivers. I am not getting any younger!!