Just to add my ha'penny...

Until recently I've always run Pirelli's (on 30, 32) & loved 'em - however, as my dealer knows that I do a lot of commuting on the bike they suggested I try Sportec M1's.
I didn't like them at first but decided to thoroughly scrub them in and give them a bit of time but they got no better & I couldn't get used to them! They just didn't fill me with any confidence & had no stability.

Last Monday evening I took the pressures up to 36, 38 and it's like riding a different bike! I can corner with confidence again!
I also took them on the track on Tuesday on the same pressures & they were great! (Tho' not as good as the Corsa's!)

I don't use my 999 on the road any more but run 31f and 28 rear on track - with supercorsas