This has not been my typical experience for lunch/dinner, although I have never had breakfast in the dining area. My breakfast complaint (perhaps should go on the Trivial Gripe thread) is that I always have to wait for bacon to be restocked in the buffet.
As for the wait times, they depend a lot on the banks of United flights. At 1:30 PM the wait time is 45 -60 minutes. By 3:30 it's 0.