I haven't had any crashes yet since the update.
Battery life is something I've always managed. Some things I do:
1. Keep Wi-Fi turned off because it seems to endlessly "hunt" for a connection. That said, it's possible to go into advanced settings for Wi-Fi and turn off Network notification, Auto connect and Notify AT&T network. That will stop it from hunting all the time. The downside is, I have to turn it on when I need it and remember to turn it off when I'm done. It's become a way of life for me. (I'm actually a lot more concerned about controlling what it connects to than anything, actually. When I'm at home, I leave it on and connected to my own network.)
2. Applications will devastate te battery quite regularly. I have:
2a. Turned off mail notifications for all mail services
2b. Turned off social media notifications for all social media
2c. Turned off auto updates for any other active applications
2d. Turned off active screen savers
2e. Changed the wallpaper to an image with more black and fewer bright colors
2f. Some apps simply consume power unreasonably. I delete them and don't use them. Bad programmers!
2e. When I say I turn off notifications for mail, et al, it's because I don't need to know every time one of my FB buddies posts up about the color of his doggie's latest poopie. When I want to get on FB or check my e-mail, I turn on the connection first, then surf the site at will. Then I turn the connection back off when I'm done. Same with e-mail or anything else that needs a connection.
3. I only use mobile data when I need it. The mobile data radio REALLY hits the battery hard for some reason. I can feel it heat up in my hand if I spend a long time surfing the internet and the battery goes down VERY fast. Of course, I generally keep it turned off, regardless, because I don't want to pay for data overages, even accidentally.
4. I calibrated my battery. I only had to do this once. There are instructions in this forum on how to do it and it seems to have helped my battery last a LOT longer.
--Wag--