Personally, i really like the MOE's. The circumaural Momentum's suffer from really poor seal and loss of bass response because of the sliding mechanism. I found i had to slide them slightly further down so that the top inside edge of the cups were just touching the tops of my ears. That way, i could recover some of the bass and get a better seal around the lower half of my ear but were extremely painful after about 45 minutes (and i don't even have a big noggin).
Also, I couldn't angle the Momentums in the x-axis plane like i could with the MOE. I can't remember too well as i sold them on pretty soon after buying, but i think the full sized ones were rigid in the x-axis, whereas the MOE can be angled so that there is even pressure on my ears back and front. I am sure someone can correct me if i am wrong on this, but i don't remember there being horizontal adjustment on the ear cups of the original Momentum's to enable them to tilt.
Compared to my Amperiors, the MOE's fared pretty well. The signature is similar which is why i like them. The Amperior has a bit more sparkle to them and better bass resolution. The MOE's are far more laid back but not so laid back that it becomes muddy, like i found with the B&W P5's. I also found the soundstage surprisingly good for the MOE's although maybe not as good as its full sized sibling... but better than the Amperior.
I was really looking for a commuting set and thought the v-moda m-80's would do the job. However, unlike a lot of reviews that i read, i found that the M-80's leaked like buggery. It was very noticeable on the London tube and when the wind was blowing you could hear draft coming through the V-Ports (it gets pretty windy in the UK!). Maybe it was just my pair which was defective... Maybe some others on here can shed some light on whether they experienced the same thing. The M-80's also sounded positively anaemic compared to the MOE's. M-80's have lovely mid resolution but it is the kind of signature which can only be appreciated in silence and sitting still for the detail and SQ to shine through. I guess my lifestyle is more on the go and a bit of a basshead, i suppose! Guilty as charged.
Anyway, i found the MOE's to be great for out and about. Enough isolation and bass/sparkle to allow me to enjoy my music but not isolate me so much that i wouldn't be able to hear what is going on around me. They also look great (up there with the M-80 and P5's), the sliders are firm and won't lose position and are light/small enough around the neck so as to not hinder movement.
