Ok so I've had a few minutes riding... the hold is really really good, bite good, noise TERRIBLE (being made worse by riding indoor I guess)!! It seems to have warped pretty easily which I kinda expected, I wanted 3mm thickness (and could have got it at 4x the price) but made do with 2mm... One strange thing is that if you do a large move involving a lot of brake force, if the brake slips (rare) it seems to instantaneously melt the resin and stick a layer of pad material to the rotor! This comes off very easily though and doesn't affect the brake performance... All in all, was worth a shot, performance is fine (probably better than steel), maybe needs some ironing out before it's worth using for any period of time.