I tried out Dex earlier, and it felt like it got improved by a lot. It heats up less quicker from my 3 hour use, and only drained like 30-40. I can't talk much about battery life since I charged my phone like 3 times today from 85% since I am a power user.
What happened to me is that my phone would die within 5 hours with light use and three of those hours were screen on time. Now my phone made it through the entire day without dying which I found to be interesting