I'm running APs and Pagids, they work very well together. I did several stops from over 180mph at the 30-130 day at Marham and they were really strong. No juddering afterwards just some slight discoloration of the discs which cleared after a few days normal day to day runnning. Only negative point is a bit of squealing from the pads at low speeds.
Best place to buy the discs is Tim at Circuit Supplies, tel. 01525 385888 and Jamie at Evotune does the Pagid pads at a good price.
Never used Carbotech, always used Ferodo 2500 in my Evo so can't really comment. I'm sure if you contact Ian at Carbotech he can give you an idea of suitable compounds for the GTR or were you thinking of trying Pagids in the Evo? I think Ross is now selling quite a lot of Pagids for the Evo fitment and Jamie at Evotune would also have an idea of suitability.
I've just fitted Bendix Titaniumetallic pads all round, bedded them in tonight and they feel fine so far, pretty much the same feel as stock and that's all I'm looking for, and for £165 that's a reasonable price. Will report more after a few hard drives if anyone's interested, but I get the impression that many GT-R owners don't like 'less expensive' parts.