I don't have one, but a mate just installed one he bought second hand in his '03 KTM 525 .. he's suffered badly from joint pain and tendinitis in his clutch wrist over the last couple of years.
His comments were ... this thing slips badly when RPM's were low ... eg. 4 gear cruising then open the throttle....
He did some research, called rekluse who recommended removing some of the steel ball bearings and insertings some tungstan ones. He replaced 5 (of the 30) steel ball bearings with tungstan ones and immediately found it was heaps better ... engaging at lower rpm's.
He ordered another 5 and got it almost perfect. The downside was with all of the extra inertia and weight, the idle had to be turned down so it only engaged when he opened the throttle.
We ride heaps of single trail (zig zag between trees which your handle bars scrape both sides) also in and out of creek beds and then open mountain climbs.
His only comment was that when locking up the back break full noise into a berm, then blasting out ... he stalled about 1/2 a dozen times (due to low idle).
So the strength of engagement had been dialled in, but the rate of engagement could be changed by installing a stiffer spring. Then he could increase the idle slightly and remove the stalling.
Overall, he's paid $450AU so far and with the amount of tweaking possible he's REALLY REALLY pleased; so much so that if I ride the bike I might get one for my CRF450
BTW, he's still got his hydraulic cluch installed and uses it rarely ... but he reckons that 2nd gear race starts are unbelievable ... so much so that it's scary trying to keep the front wheel down!