I honestly don't know what all this discussion about battery problems is all about. I am easily getting through a day of use without recharging. In fact, it is down to about 40% when I come home at night.
I constantly check e-mail, use the organizer features, have it connected to the car via bluetooth, use WiFi, surf the web on it. I don't watch videos or play games ever, and I have all the Samsung smart features disabled (because I find them to be silly gimmicks). But, my battery life has been stellar.
Look at somewhat objective tests in sources like Consumer Reports. The S4 actually does fine (quite good even) when it comes to battery life.
The build quality issues have ups and downs. The phone is solidly built, and creak free. But, the casing is ridiculously slick and it is a finger print magnet.
You'll want to put a more grippy case on it.
The Moto phones tend to have better build quality, but I had such a poor experience with my Droid 2 Global and Droid 3, that I will likely never buy another Motorola product.
Overall, I really like the S4. I do feel that the phone would be better without touchwhiz and all the Samsung gimmicks, but that stuff is all easily disabled.