I've flown Sabena years ago on a trip Duesseldorf-Bruxelles-Barcelona. BRU airport was dreadful, but the flights (in Y) were OK (short hops, though). A colleague flew DUS-BRU-JFK a while ago in Y and said it was OK, but not great. (of course, there are rumours that Sabena stands for "such a bloody experience, never again..."...)