mobile

I'm planning on buying an Xperia z3 Compact. I currently have verizon so I know I'll have to switch to either att or T-Mobile. I've read that some people were having issues with getting lte service with att where they were not getting calls or texts with the lte on but haven't heard much good or bad about T-Mobile. The threads about lte issues were from last year so I don't know if anything has changed since then. Some people said registering their sim with an iPhone imei either but others said it made no difference. I do know someone who I could get an iPhone imei from but don't want to waste my time if it doesn't actually fix anything.

I'm open to trying either carrier since they're both contract free but would rather avoid the hassle of switching carriers 3 times. Att does seem to have a better reputation in my area (Long Island, NY) as far as coverage goes.