Is it true that iPhone 4S has battery issues?
I charge my iPhone 4S overnight each night, but I could probably get through multiple days if I was careful. 

Currently, I'm not careful about battery life. I listen to podcasts on the train to work, make calls, surf the Internet on 3G and WiFi, and listen to streaming radio on WiFi pretty much all day at work. With all that, I get ~16 hours of battery life, which is much better than either my old 4th gen iPod touch or my Palm Prē.

Batteries can vary by model; the people who wrote the articles you mention probably just got crappy batteries. They should take their iPhones in to an Apple Store and Apple'll probably replace them, as the batteries are clearly defective.