I'd actually go so far as to say this:

ALLLLLL the airlines these days lack in customer service!

If you do not have status (probably the case if you are new to this) then fuhgetaboudit. And United is particularly obvious in its treatment to the lower classes. If you do have status, this does not mean they wont screw up on you too, making some even MORE upset because they really should not screw up there.

be prepared.