I use these tires for 5 to 7 track days a year, have two seasons of track days on them, and drive them 5 to 6 months out of the year as my daily tires in the summer in Seattle.
These tires are great on the track! Predictable, consistent, and very little fall off after a 25 minute session. I run double sessions with students as I also teach for the local Audi club as a track instructor. These tire take A LOT of abuse during track days, and they always are there for you during a day at the track.
Daily driving they are a bit on the noisy side, BUT they are solid in Seattle rain if you use your head, and the AWD of the S4 to your advantage.
My one gripe is that the tire does not come in a 245x35x18 as the rims I use are a wider offset, and I get just a touch of tire rub on the inner fender wells.
I would totally recommend this tire to anyone looking for the tire you can drive to the track, kick butt with, and then drive home and around town on.