This forum has gotten pretty quiet. But unfortunately, the problem remains in the newer iPhone 5s, according to own own experiences anyway.
I had a flawless iPhone 5. I kept it in a case and treated it very well. However, something really strange started happening to the anodized antenna. The top part of the antenna , on the front of the phone, began to warp. I noticed because the antenna was not flush with the glass on the front anymore. Because of this, there was a gap between the antenna and the glass. It kept getting worse to the point where you could easily tell there was something wrong with the phone's aluminum antenna. In fact, I could see the inside of the phone due to the antenna developing this strange warping. Finally one day, the screen went dead. I sent it to apple and they sent me a replacement. Week 50. This one's screen was fine but the antenna had ragged scratches all around the power button and volume buttons. I took it to an apple store and the genius said he had no problem in replacing it for that. The one he brought out was way worse. In fact, this one also had large pieces of dust under the camera lens. Bad QA. Anyway, he said he could not do another replacement. I told him that this one was way worse than the one I turned in. He said he was sorry but couldn't do anything about it. I sucked it up and took it home with me. As I was putting on a screen protector, I noticed a dead pixel. I took it back to the apple store and got another replacement. This one had something that looked like dried glue on the antenna. It could not be removed. Upon closer inspection, I determined its probably a piece of aluminum that was on the antenna that was stuck to the antenna before being anodized. The piece was anodized on there. It could not be removed without damaging the antenna further. This one also had large pieces of dust underneath the camera lens in addition to the glass around the lens being chipped. I finally have given up and have my iPhone 5 to my fiance. I am using my 4S again and I notice the superior quality of the 4S.
I really like the design of the 5 though and really wish it was better executed.