I'm running Yokohama Advan Fleva V701's in the OEM 205/40-17 size. I've been happy with them, the turn-in is good, and the ultimate grip is good.
I agree, I haven't felt the need for a separate summer/winter setup because it doesn't snow much here, so I have chosen to use a summer tire because I want better handling than an all-season provides, but not an extreme summer tire so that it will be more usable in cold temperatures.
I'm retired so the few times that it does snow I can just stay off the road for a couple days, because I know that my summer tires can't deal with snow.