Hi, I'm SF based but my office is closer to the PA store. I prefer the PA store for location and overall it seems more relaxed to me at least during the week when I go after work. SF always seems very busy to me and when I am working in the city I am mainly using MUNI to get around or walk. I don't disagree with the SF having more stock, and I have oftentimes walked out of the PA store without finding what I want.
But I do enjoy my time at the PA store - we chitchat talking about life stuff like where to eat, vacations, movies, etc. This is my experience during the week, I usually leave work a little early to go to the store. I'm sure it's a totally different experience on Saturdays!