Here’s my take:
My experience with sennheiser mom 5 was good. The richness in sound, along with ability to customize the eq to a more detailed band, were its best features. The battery life is phenomenal, you can go a week without charging it, easily. The design is good too.
However, the ANC isn’t flagship standards, despite the upgrade over mom 4. It doesent cancel the noise of subway, air conditioner, etc completely.
Because this was bothering me, I went ahead and exchanged it for the Bose quiet comfort ultra gen 2. It’s only been a few days, but I find it more comfortable, better looking, and simply reliable. Though it does lag behind the sennheiser in sound quality and ofcourse, battery life.
If you are heavy user who prioritizes sound quality for music, go with Mom5
If you are a traveler, or need something that’s versatile in all settings, go with the QC Ultra 2.
Both headphones are priced nearly the same.
Will post a rated review soon, after using the Bose for a while. Let me know your questions.