I have the same product from BofA. I bagged my UA RCC and AS BR memberships late last year. I am also SFO-based, but not flying all that much this year. I've made quite good use of the PP membership. The only weak points for me so far as been:
(1) T-3 @ SFO. However, there have only been 2 trips where I've been over there. Once when I arrived quite early, after dropping my luggage off @ UA, I took a quick walk to the CO lounge in T-1 (landside, not airside as you had mentioned) and used that one.
(2) Guest fees. I don't need to incur them very often, but they can add up rapidly.

If you fly AS out of SFO, it is very good because you get BR access as well as NW lounge access in the int'l terminal. Otherwise, the AS int'l flights have no lounge access.