Spyre's have the same fitting as HyRds, I fitted a set of these Clarke's semimetallics a month or so back:http://www.chainreactioncycles.com/clarks-shimano-deore-m515-m525-elite-disc-pads/rp-prod55871
I was so impressed that I ordered another three sets.
Of course, part of that might just be that they were replacing some old pads that were completely knackered, but nonetheless I get the distinct impression that the bike can stop on a sixpence now. Excellent bite, haven't had the opportunity to notice if the fade has been improved by the cooling fins on the back...
Also, new rotors are cheap - can't see the point trying to preserve them by using organics etc (unless you have spent a fortune on fancy-dan rotors, which I haven't).