Dunno what was going on with your phone, but I've done over 24 hours with mine, easy. Not rooted. Camera is horrible though, I hope they help it out a little with the update. I've been a tech for over 2 years and a lot of problems came out of Samsung phones, Moment Intercept, Instinct, Epic, (GS1) I will admit they have brought up their game with the Galaxy 2 and 3 but the original galaxy for sprint was horrible and battery life on the 2 wasn't the best either.
The Evo 3D has some good things but not enough to say it was better than the original or GS2. The camera, IMO, was a gimmick. I'm mean, 3D? Really? FTR, 5MP on a "high end device" kinda brings it down from that status. I hated them for taking the kickstand out.The dual core and expanded memory were great, though and of course, Sense 3.0 FTW lol. Battery life was awesome, like I said before, maybe you had a bad battery. Touchscreens were bad, they are the most replaced in our lineup as far as malfunctioning (Not shattered) Other than that, it is a good phone and hopefully with ICS, it will be a better phone.