The airlines I fly (almost exclusively) are United and Delta. I don't now and don't think I ever will fly enough to reach mid tier let alone mega tier through actual BIS and so I feel comping is my best shot to fly to where I want in the manner I want. I'm much too frugal to pay for Centurion or Elite clubs but since I don't conduct business, it's not really important. What is important is:
1. A comfortable ride (regardless of the airline)
2. Ease of check in.
3. And as PremEx once said "it's the little bags of peanuts"

Because I don't know who will be using SFO as a hub (SWA and JetBlue fly out of Oakland), who will be in what alliance, what kind of planes they will be using and what their promos are, I feel it's important to hedge my bets.