I've got a set from EBC for free. So, after my current HH is done (also got from them for free), I will try and likely permanently switch to those - for the feel and longevity.
I glazed my EBC HH a while back (those high speed runs before my exit - braking from 170 to 30). I was riding to the track one day and the traffic stopped ahead. I started braking - and nothing - the bike barely slows down. I applied more and more braking effort and locked the front and went down. The funny thing was there was a funeral limo behind me, so the guy slowed down, stopped and blocked the traffic off for me - thanks buddy.
I was scratching my head, until I pulled the pads out - glazed about 50% of the surface. I contacted them, a coule of my emails got crossed and two people independantly sent me one set of HH, and one set of extremes.
Since we are on the subject, I think it's important to check your pads once in a while to make sure there is no glazing, especially after some aggressive braking - like during track days (melted silverish looking metal from the disk gets embedded on the pad surface - and you know metal on metal doesn't provide much friction). If a glazing occurs, just take the pad out and move it around on 200 grit sandpaper on the flat surface (don't sand by holding the sandpaper with your hands) until the spots are gone - that's per EBC rep suggestion. Then, break them in as usual - which actually at this point takes just a half dozen of braking attempts.
