Is there any chance an unlocked AT&T 640 variant would work on Verizon? The bands seem similar, but I'm not sure what governs how well cell phones work on different carrier networks. Most of the VZW bands are there when I compare the specs between the Icon and 640. I'm guessing there is some carrier firmware required also.
I recently unlocked a Lumia 520 that was an AT&T GoPhone. I like that I do have a little freedom to move it around, at least between AT&T, T-Mo, and the small VNMOs. I'm considering moving to one of those carriers if VZW doesn't get the 950 in the fall. I like VZW's network, but want to stick with my phones of choice.