Well, it may have had a lot to do with the level you listen to. When amps max out, they start to compress before they start to distort (it's actually the same thing at different levels). When they compress, it'll still sound okay, except things will start to blur together. People like you definitely need multiple drivers, because most single-driver systems (headphones, single-driver speakers like Lowther-based speakers, Quad ESL's) don't go loud well. IIRC, you don't like Quads either, so...QED.
At the levels I listen to, I have no problem hearing things I've never heard before. (Wait, that didn't sound right...)