As of yesterday I've now moved my ST200 from CS3s to AS2s. Tyre size is 225/40/18.
First impressions? Positive.
I think they might be slightly quieter than the CS3s, although that could be placebo.
Responsiveness seems spot on, possibly even better than the CS3s.
Rainy today and not a hint of an issue.
In short, first impressions are that they are at least on a par with CS3s. I'll need a fair bit more time to give a proper verdict, not least to compare their wear rate, which in my mind was the one big weakness of the CS3s.