Mintex are good stuff, I've used their pads 1144 and 1155, and discs, but only in vented plain not grooved etc.
I had no problems with warpage, but if they get hot they will warp like any other disc, the pads I found VERY dirty and soft, did the job, nice feel, more of a very fast pad than a let's drive mental pad imo, the last set I had I gave away to Retro Al, they'd only done about 200miles, certainly way way better than the DS range.
I have a set of Mintex discs which are on my dads xr4i now with my old cossie 4 pots(with alloy pistons), they must be 10 years old by now easily and still perfect though my dad does drive easy, I drilled them at the time as they become much better then.
tabetha