I switched to the X Force Pro last year and haven't looked back since. Great frame for me, as I was looking for something sub-12oz, but still had control and enough stability to handle hard serves & heavy topspin (I'm a 4.5, but routinely hit against 5.0 college players).
It took a month or so to adjust from a 20mm straight beam (C10 Pro) to a tapered frame, but other than that, absolutely no complaints.
I had hit with the M Pro No 1 for a month prior to buying the X Force Pro, and while a tad stiffer than its predecessor, Pacific still managed to retain the Fischer feel (my understanding is the X Force Pro is essentially the Black Granite Pro No 1 that never made it to the states). This is a great all-around frame that allows you to swing through the ball with confidence.
Now, if Pacific can just find a way to market these things...
"Nobody beats Vitas Gerulaitis 17 times in a row" -- Vitas Gerulaitis, after beating Jimmy Connors on his 17th try.