I had to upgrade to a 4G phone when my HTC Droid Incredible 2 had a bad charge port (and I couldn't go 2-3 days without a phone). I had been very happy with my 3G coverage. No problems. Unfortunately, after moving over to 4G I've had nothing but issues. I would say a good 80-85% of the time I have NO data coverage AT ALL (in Louisville, KY). There is no reason why I should hardly ever have data coverage. Why am I paying for unlimited data when most of the time I cannot even use it? I can't even get 3G data on the device.
I wish I never had to upgrade because 4G is a complete joke, IMO.