There are alternatives to add extra battery life. There are portable chargers and even batteries in a case that you can stick to the back of the phone to add capacity. If the eLTEvo is as popular as it looks like it's going to be - I bet there will be special add on batteries or even replacements that you can take the phone apart and replace the original with. They might even come out with a conversion to convert it to removable battery.
I had a Nexus for 4 days. I couldn't return it fast enough. HATED that phone. Slow at times, laggy almost all of the time. Terrible screen with an odd color cast, (whites were yellow). Battery life stunk. My Bluetooth would never re-connect. Had to constantly turn BT off then back on again every time I walked ten feet away from the phone. My OG Evo always reconnects automatically and usually doesn't disconnect until 30 to 200 feet away.
Jack