I did some looking, but found it a bit troublesome to figure out - would this phone work on Verizon just fine?
Their network is also incompatible with the radio in this device.
That said, enforcing it is another matter.
http://buzzmachine.com/2013/09/17/verizon-caught-red-handed/
If you read forum reports, it seems people are activating it by using IMEI numbers from other tablets and whatnot, but Verizon is not making it easy, or (IMO) living up to their contractual obligations.
I've heard Tmo is good in cities from friends that use it, it's the non-city areas that you'd have to watch out for.