I just got the Momentum On Ear from my local Best Buy for $99, as mentioned earlier in this thread. They're back up to regular price online, but my local store still had them at $99. They only had black and ivory, I got the last black one (sorry).
I really like them, I was worried about how small they looked, but they were able to form a good seal. The treble is a little bright, but once you EQ it down you can tell that it's very detailed/clear, and smooth (no harsh peaks). No midbass hump, which is fantastic, and I don't think the bass boost is too much (a common complaint). Bass extends pretty far but not all the way down to the very lowest notes, and it can be a little muddy, but only in comparison to higher-end stuff.
As a previous owner of the Amperior I am pretty confident in saying that I like these more overall. They both have the same recessed mids, but I think the Momentum does the rest better. The bass is a bit of a letdown, but the treble detail and smoothness outweigh that for me. Then again I listen to drum'n'bass so I have very high standards for bass extension. The extension in the MOE is more than enough for most non-electronic genres.
The only problem? Now I'm tempted to return these to move up to the full size Momentum, or the Urbanite.