My wife runs a bone stock 04 KFX700 and I love it. I dont have my XX yet, But I picked it for IRS and a manual clutch. Im sure you will here a bone stocker VS bone stocker review from me shortly in this thread.
Ive raced several piped, filter, clutch modded, jetted KFX700's with my bone stock XX and they get me outta the hole but thats it. By the time I hit third I've already reeled them in and start inching by them. Close races, but stock on stock isnt even close.
I used to ride my Dad's KFX alot when he had his and they are fun quads for sure, but the CVT setup just robs that bike from being crazy in a straight line.
I didn't realize how fast they were until my wife bought one. I came home to find it sitting in the garage. I took it out on the pavement, cracked the throttle, and nearly lost it over backwards as the front wheels lifted. It has continued to amaze me ever since.