Weirdly, my Bridgestone Turanzas on the Polo GTI seem to handle moderately low temps (3-8C) better than Summer temps (15C+) in terms of grip and traction. They're still incredibly noisy though. I thought VW had perhaps scrimped on the soundproofing until I got a go in the reef blue GTI at Lookers Scotswood Road on standard 17" wheels (Michelin Primacy tyres).
I'd always look to Michelin for aftermarket tyres - they not only start well, but they perform all the way down to 2mm. Some "great" tyres fade right off when they're half done.
I'd always take professional reviews with a pinch of salt, especially on a new tyre with no user reviews.
