Another fan of the Michelin Pilot Super Sport, just recently had a pair on the front to match the rear. Last weekend I had the chance to try them out for real. I know the weather has been warm, so the Tarmac is lovely and warm but the grip in all corners was great, fast bends, exiting roundabouts was no problem at speed no hint of them trying to break free. Heavy braking from speed wasn't an issue , no tram lining or wander, brakes could be better though ! Extra cost could be a factor in 19s but I'm very pleased.
If you have a west London location I can recommend Rich at RTS Ruislip a great guy and will give you a very good price, talk to him before you order from black circles. He always looks after my alloys, top man.