I have an FSR Comp, heres what I have changed on it.
Set-up: Thomson seatpost, python gold tires, flite saddle, easton EA-50 stem, also cut the bar shorter, eggbeater pedals.
Its a great bike, the frame design is excellent, it does bob a slight bit under power, not noticable to the rider, but it is visiible. Its a champ. I really don't have one complaint about it, and I usually forget that the bike is there. So thats enough said.