I've seen some people saying IEMs sound better, and some saying they are almost always inferior.
I, personally, feel that IEMs, do normally sound better than full sized headphones in the same price range.
When I compare my Brainwavz R1 ($35) to my Monoprice MHP-839 ($30, and they're considered to be some of the best budget cans out there), I always feel that the R1 comes out on top in generally everything. Clarity, mids, soundstage, bass control, and isolation all sound much better on them.
What do you people think? I'd like to get some more opinions on this topic.