The Sun Kings have been doing this long enough that the set isn't a greatest-hits shuffle — they work through catalog deep enough to keep the people who know every B-side occupied while still landing 'Hey Jude' for the crowd that wandered over from lunch. The plaza setup is open-air, so sound varies by where you plant yourself; closer to the stage, obviously, but the benches along the south edge are in the shade if it matters to you.
Food options are thin on the plaza itself, but there's a cluster of trucks and carts on the Hyde Street side most weekday afternoons, and Souvla and several other sit-down spots are a five-minute walk on Polk. Don't bother with street parking — the meter enforcement on McAllister is aggressive at noon. BART or the 47 bus are the move.
If you've got two hours: grab lunch on Polk first, arrive by 12:15 once the crowd has settled, stay through the set, done by 1:30.

