Coming from the Sony WF-1000XM3, I have the following to say:
- Music quality: With the Sony, I was blown away. With the Sennheiser, I cried.
- Call quality: I had issues with the Sony. With the Sennheiser, it is better, but these headphones are not intended for frequent phone calls in noisy environments, etc. If you frequently talk on the phone and it is a priority for you, then go for Freebuds 3, Buds+, or AirPods Pro.
- App: I have always had issues with the app as my ears don't have the best shape. Sony offers many eartips, so logically, one will suit you, but for me, it was confirmed once again that they didn't have the perfect fit, and I couldn't use them for activities like running or cycling as I was sure they would fall out. Also, due to the mediocre fit, I didn't have the best passive noise cancellation. On the other hand, I was completely satisfied with the Sennheiser! They don't fall out at all! It's the first time I see such a good fit, and due to their durability and water resistance, I can exercise without worrying about them breaking or falling out.
- Active Noise Cancellation: I have the impression that both devices are at the same high level, with a slight advantage for the Sennheiser.
- Battery: Both are excellent in battery management, and I can't find a difference between them.
- Case: The Sennheiser case is of higher quality and smaller, which definitely helps with portability.
- Connectivity: With the Sony, I noticed some small interruptions after a while, mainly when connected to the laptop and not the phone. With the Sennheiser, so far, it's rock solid. I will update if I notice any changes.
Conclusion:
If sound/music quality is your number one priority, then you bought them yesterday. If you appreciate it but aren't crazy about it, or/and you don't want to spend that much money, go for the Sony. If you need to talk on the phone, then forget about both and go elsewhere.
To put it differently, if you were searching on websites for headphones that offer high-quality music sound and found the Sennheiser, then buy them (or if you don't have the budget, go for the Sony). However, if you were generally searching for true wireless earbuds and happened to come across the Sennheiser, it's more likely that you will be satisfied with something cheaper (but not cheap), like Freebuds 3, Buds+, or AirPods Pro, which also offer excellent features for their price.
Update 23/6: Probably due to a firmware upgrade, the call sound quality has significantly improved, so now I officially have no complaints about the headphones.
Update 29/11: I recommend that those who have purchased them order the Comply TrueGrip™ Pro from here:
https://www.complyfoam.com/products/tru-truegrip-for-sennheiser-momentum-true-wireless/
They have incredible passive noise cancellation, as if they were earplugs, while being made of soft material that adapts to the shape of the ear canal. I'm telling you, I can't hear anything else except my music! Not even my girlfriend when she yells! Unbelievable! It's a must-have purchase!