I have a M90-13T. It lasts anywhere from 4 to 6 days depending on the amount of streaming. I also have a Linx Quattro and have been switching back and forth between them. I like the Marvel because of RogerDirect (I have a Pen and Select) so I don’t have to change out the battery door to add a Roger receiver like I did on my Ventures and Beyond.
For streaming, I think the Marvel sounds better since it uses full bluetooth rather than a paired down version like the MFi hearings do. The one thing that keeps me from really liking the Marvel is the use of the hearing aid mics for phone calls. If you are in a quiet environment, they work great but as soon as you try to make a call in a noisy place it’s pretty much useless. I’ve had better luck using the Quattro (with the builtin iPhone mic) in noisy situations. I really wish Phonak had a way where you could use the PartnerMic as the mic for phone calls. They could make it fallback to the builtin mics if the PartnerMic is not connected.
I know Advanced Bionics is going to release a new processor based on the Marvel line. This is another reason that may keep me using the Marvel. At least I’ll be able to stream bluetooth to both the hearing aid and the CI without having to resort to my Roger Pen/Select or telecoil.