We were at the YC in January and I was amazed at how small Beaches and Cream was. There was around 10 tables total. We had hoped for a kitchen sink, but the place was booked and there was a decent line for take-out to boot. I thought they did take PS's because they had a hostess CM calling out the names of parties to be seated. It must have been a walk-up list. So I'd say if you have your heart set on a KS, go during off periods of the day or be prepared to wait a awhile.