I noticed the battery drain start happening with version 1.4.844, but it could be happening to you on your version as well. It may be related to band 26 becoming active in my area as well, but I'm not sure. This update and b26 happened within a day of each other so I couldn't find a difference.
As for the use details screen: Settings > Power > Usage > The App you want to see
I went and disabled SCO from the Automatic Connections menu under Mobile Data, and my battery life is significantly improved with no other changes. I've had my phone off the charger for 3 hours now, with the screen on for 15 minutes of that, and some texting/email, my battery is at 90% instead of the ~70% that it was at the same time before I turned off SCO.