I don't know much about verizon, but I have been extremely happy with AT&Ts Next Generation GSM/GPRS service!! I was on AT&Ts older cell network, and was a previous Sprint PCS customer, and had the usual complaints with both - dropped calls, sucky reception, no calls in hotels, etc. I was looking at switching providers, though I had not heard of any being better, when I tried the GSM/GPRS service. It does not work as well in remote areas yet, as it is still a new/smaller network, but in cities and larger areas, it rocks!! I have great connections and signals almost anywhere - even in Vegas hotel rooms. If you are in remote areas a lot, you can also get a multi-band phone, which will allow you to have GSM/GPRS service in the city, and use normal digital cell in remote locations. Check the coverage maps at their site - lots of free phones with new service for the holidays too -
http://www.attwireless.com.
Hope it helps
