Hi, I have not actively compared the two per se. I am also relatively new to the audiophile world and may not describe things properly, so you may take this with a grain of salt.
The Shozy seems very source dependent, sounds good with the work PC. I can't stand using them with my phone, however, the Samsung Galaxy S5.
The Sennheiser Momentum is a little of the inverse.
They are both warm sounding with the Momentums almost downright hot. The bass quality is better to me on the Momentums, but I like the Shozy bass level more. They have a nice little thump to them. The Shozy has a more forward midrange than the Momentums, which I really like. I also think the Shozy presents more detail than the Momentum. The downside of the Shozy is the treble for me, but even still it is not bad at all.
Funny thing to me is that the Momentums are recommended for hip hop and electronic music because of that bass, but I enjoy the Shozy more for those.
Overall, I think the Momentums have a more fun sound to them, but I am accustomed to the more analytical and vocal-centric Audio Technica house sound. That leads me to put the Momentums away after a few hours of listening.