In general, I'd say too little detail in baroque music and Mozart, and too much swooshing around in everything else. I can appreciate the thoughtful swoosh when appropriate, but I don't enjoy an overall wallowing. I am also suspicious for some reason of performers who look up at the ceiling while they play, or stare off into some distant place. I know sometimes this is a genuine moment of really experiencing the music, but sometimes it's just a mannerism to make the performer look more expressive. Why do I care??? It shouldn't matter! It's a flaw in me, not the performer. Oh, and "tapping" the keys: making a percussive noise in the process of playing staccato. Sometimes this suits the music, but often not.