Battery life has sucked even after I went to drastic measures to make it good. I noticed that if I move about town, the phone consumes enormous amounts of battery. It gets hot and doesn't seem to show what is really using the battery. I don't understand this. I'm sure it is google now, but I've turned that off before and it didn't seem to help. I've even turned of location services and it didn't help much.
Most recently I have swapped out the launcher and now run Nova. With the samsung launcher, it was taking 2-5 seconds for the camera to launch from the double tap of the home button. With Nova, it is as fast as can be.
I never believed just how awful samsung's launcher could be, but it lives up to the hype of being horrible in just about every way.
I'll let you know how it goes ditching TouchWiz, but so far so good. I never used any of the touchwiz features anyways, so they really weren't needed. The screen is too small to do split screen or floating windows. TouchWiz must consume every ounce of memory in the phone!