I have noticed my battery lasts about 50-75% as long as it did before the update. I used to have this issue, the last OTA update fixed it. Now it is back.
With ICS I usually ran about 800mb ram, with JB iv noticed it going as high as 1.2-1.3gb ram. But as soon as i kill all the apps, i click it again and 30 apps are already running.
Perhaps a wipe/restore is in order... Perhaps root and go back to ICS... Maybe they will release a small OTA to fix bugs like before..
All i ever want was the News & Weather Widget. I cant believe i waited 5 months for this...