At 10K my stock 2005 clutch was replaced (5K Stock, 5K all mods). The plates LOOKED brand new, and the mech even broke out the calipers to measure it. Hardly touched.
We surmised it was the springs being too weak, and over 10K of use couldn't stand up to the torque WOT past 3500 RPMS. So, FWIW, a set of new, or stoutre springs would have theoretically solved the problem.
Barnett Clutch/heavy cable installed (which comes with heavier springs) and roughly 9K later under certain conditions (meaning below 75 degrees and low humidity) my bike is making substantially more power) she will slip.
I also believe it is the 2005 clutch internals that have worn and are now causing the lack of clamping, which needs to be addressed, certainly before I make any more mods or move to a cooler climate!