Just FWIW: I've been running XP10 front + XP8 rear for a while now. It's a really solid bite on the track, and it's less prone to ice-mode than the XP8+XP8 setup I was on before (well that and I've learned to reapply quickly at the first hint of ice-mode, too). I've just been leaving them in on the street, but I don't drive that many street miles anyways. They work fine cold, but you do have to be careful of the bite (that you don't surprise someone behind you).
I also duct-tape off my Stillen brake ducts while driving on the street, to help the pads get/stay warmer (helps with maintaining the bedding too). The dust and noise probably isn't for your everyday street driver, but it's manageable. Flat black wheels helps, I never worry about cleaning pad dust off the wheels
