I mean as budget airlines go, they're actually not at all bad. I recently went to Barcelona on Vueling and returned on Ryanair (due to flight timings), and I was easily twice as irritated by the flight back vs the flight out.
(They do, however, use Dublin airport's worst 'gate', 335, which is _actually_ a bus to a small fake terminal separate from any of the main ones.)
In my experience they're the worst. I have legs and 29" doesn't work for me. Twice they've had check-in so slow we all panicked thinking we would miss the flight. And they've been the worst I've ever experienced during IRROPS