FWIW, I was feeling battery & performance degradation on my 2yr old Maxx as well. Factory reset it a month or two ago, and that definitely helped with performance, not so much with battery. I'm reasonably sure that daily wireless charging 700+ times now has physically degraded the battery, from heat.
I was hoping to see substantially better battery life from a brand new DT2, but alas, not so much in my first couple days with it so far, about 12-13 hours. Now, that's probably a couple hours better than my Droid Maxx in its current state, plus I'm probably using the DT2 more than usual since it's new and interesting. But I had higher hopes for ~30% battery left by early evening, that hasn't happened. To it's credit though, I'm a pretty heavy user, with Pebble smartwatch and lots of screen on time (SOT), 1 hr 44 min in past 7.5 hrs today. And, turbo charging is a huge help.