I had the Lumia 928 for a year before I gave up on it. The 7th phone I had sits in a drawer after being fixed by Nokia. These phones suffer CONSISTENTLY from the phone ear speaker having issues. I know it seems odd that I would want to talk on my phone without using Bluetooth or the Speaker, but at times I wanted to do this.
Every single one of the 7 phones had this issue. It took months for anyone to admit it was a problem, and after admitting it was a recurring problem, Verizon wouldn't let me swap to a different Windows phone. It is no wonder Nokia sold these to Microsoft, the physical hardware had several issues.
Another minor problem is that you have to reboot it every few days or the touch screen will lock up. I don't believe this is something they addressed, since mine was still having the issue after 1 year. All of my phones were warranty, except the first one that I accidentally broke in frustration trying to figure out how to reboot it with a frozen touch screen.