Maybe "overrated" is too strong a word, how about heard a brand name speaker and thought afterwards, "What's the big deal?" Here are mine:

-Martin Logan: nice looking, but weak, almost non-existent low range/bass

-Mirage Omnisats: still has the tinny, home-theater-in-a-box sound

-Boston Acoustics: too bright, sounds like treble and mids are turned up too high

-Bose: gee, do you guys have all afternoon?