The T1-Rs never felt 'bad' in the wet. No doubt the Asy2 will grip better in the case of an emergency stop but I can't say there was much difference during normal driving. The biggest difference was noticed when the T's got near the legal limit, they were pretty crap then, bloody good fun, mind
Edit - I did drive through some standing water on the motorway a few weeks ago and I didn't see it but the tyres held up
very well and didn't steer off course or anything. Would be interesting to see how the T1-Rs would have done as I don't ever recall them having to deal with similar. I'd probably still buy Asy2 again as, like I said, they're no doubt better at the limit, even if I can't tell any difference whilst driving normally.