I've used a few treaded and slick tyres in Spain (and UK). Tyres are a personal choice, I love Dunlops and my mate thinks they're too expensive and prefers Metzeler.
I'm of the same mind as Simon Crafar, buy the best tyres you can. Even if you aren't good/fast enough to use all the grip they offer they'll provide you with a larger safety margin if you need it.
Anyway, here's my opinions on them -
Pirelli Supercorsa SCs - Plenty grip but wear & longevity is dependant on compound & track temp. I find they don't last me very long at all except on my little RC390 (by far the best tyre for this bike, incredible side grip at full lean and as the bike weighs feck all seem to be lasting well)
Pirelli Superbike Pro Slicks - Tried these because they were cheap, they were on the bike for 2 sessions before I took them off again after a lot of rear end movement on corner entry and a big rear end slide coming onto the straight at Jerez. No warning that I was approaching the limits of the tyre, no squirming etc, it just let go. Wasn't even going that fast (top inters-ish). Supposed to last ages though, a friend of mine used them on his 1199 Panigale and had no issues at all other than the TCS light constantly flashing when he taps the gas on
Dunlop GP Racer 211 Slicks - Good grip, lasted pretty well but I didn't get full use from them. I wore them out due to poor suspension changes on my part, chasing a problem which didn't really exist.
Dunlop KR106/108s - My favourite, but cost a fortune. I've used most compounds and they've all been great. Masses of front end grip, steer quickly and give loads of confidence. Rears wear well but I found they were a bit sensitive to pressure on my RC8. It used to chew them up pretty bad if I had +/-2psi away from ideal pressures. Harder compounds last forever and I couldn't really tell any difference in grip levels. Preferred paring for me is MS2 fr and MS3 rr, seems to work well most places. I'm taking some to Aragon in a couple of weeks so we'll see how the BMW gets on with them.
A friend of mine needed new tyres for a race at Brands Hatch a couple of weeks ago, put a set of these on and instantly went over a second a lap faster.
I'm going out there with the standard Metzeler Racetec RR K3s on for the 1st day and will pop the slicks on for day 2 & 3.