I have the Extremes, and like them. They perform very well, and seem to be lasting reasonably well. I don't worry about driving in a little rain, but if it's really nasty out I take a different car, just because. The DWS's should last longer, if that's a concern, but when I was looking I didn't think they had both sizes available. Perhaps that's changed. In any event, don't mix the two tire types, as it can make the ABS not work in dangerous ways.
The only concern I have with the Extremes is when it gets cold. Up here in the Foothills it can get down into the 20's to low 30's in the winter, but dry. Summer tires don't like (are arguably unsafe) below about 35F or so, which is probably less a problem in the Bay Area.
What eHorses said... When you get the tires switched, tell them (not ask them) to use only a floor jack at the specific jack points to swap the tires. Tell them in no uncertain terms that if they fail to do so, they could total the car. Talk to the store manager if possible. Also, if you have the old wheel locks, take the opportunity to swap them out for the regular lugs. They WILL fail at some point, and trust me, it's not fun. They must use a hand wrench, not the air gun, when dealing with the lugs.