This issue with at least Verizon 4G phones is that they are no longer locked, but this does not mean they will necessarily work on all carriers, just like having a Global network selection will not make a Vzw phone work on any carrier, the same goes vice versa for phones from other carriers. One of the bigger hindrances to a phones compatibility is in regards to it's hardware, in this case, radios that don't use the same frequencies and bands. True, a phone may partially work on a service or carrier where 1 freq and 1 band match, but in the end, who wants a partially working service?