ive tried two mono trials. One was on a mod, felt very nice, good power blah blah. Other was on a stock, and it was mushy, slippy and generally shit feeling..
i have been using my avid for a few months now, and can say that i'm quite impressed by it. can't say i've noticed it fading, but then again, i don't do speed on the trials bike. it was cheap, and works better than my XTR vee brake did, so i'm happy with it.