I got the beta too for AT&T, signed up for it a couple months ago. Performance is great and battery seems to be better, but it's been less than 24 hours. All the little touches are great, like being able to turn off the annoying sound when connecting the charger and being able to dismiss the "Wi-Fi connected" notification.
View attachment 215379
How do you sign up for the beta?
I'm curious about this as well.
Someone had posted a signup link on Reddit a couple months ago, I signed up but figured it was bogus. Yesterday I got an email with an apk attachment to install the update. Looked kind of fishy, so I dismissed it, but turns out it was legit.
Also, earlier reviews of MM on the S6 said that you couldn't get rid of the "Quick Connect" bar on the notification shade, but if you edit the quick settings, you CAN turn it off.