Both the A and the B/C US Club rooms (F is currently closed due to renovation) are airy, spacious, and generally cleaner than the UA Club. Being on the second and third floor, respectively, of the terminal, they also have nice tarmac and runway views. Bathrooms at US lounges are large and clean, unlike the third-world conditions at the UA Club.

In terms of food and beverage, the UA Club has the usual array, except for the snack canisters. Free well drinks, beer, and wine, too. Pay for call liquor. The US Club has only free domestic beer and wine. Any hard alcohol they charge. To eat, they have instant oatmeal, fresh fruit, and maybe some pastries in the morning. Later on cookies, fruit, chips and salsa, and snack mix. The A lounge has soup and olives available during transatlantic departure times. Oh, and free butter mints at the desk.

My preference is the US Club, unless I need UA CSR or am looking for a drink, in which case I hit up the UA Club.

The winner at PHL, though, might be AA, which shares the BA lounge. Never been in but it looks nice from the concourse.