One common criticism of Verizon Wireless is the fact that they use CDMA as their phone technology. This matters because it is a technology primarily used in North America and so if you take one of their phones on the road to say, Europe, it will not work. This is in contrast to T-Mobile and Cingular who use GSM which is the same standard in Europe. In fact my Cingular phone works perfectly in Europe with no change.
In my area, Verizon has by far the best coverage. The cool thing about the Blackberry 8830 discussed here is that it includes both a CDMA and GSM radio in the same unit. Thus you can use the phone with CDMA in the US as you normally would and then if you travel internationally, the phone will automatically convert to GSM and work their transparently. This is provides the same kind of transparency as provided by their GSM competitors.
The other benefit with Verizon Blackberry is that it works on their 3G EV-DO network which is much faster than the EDGE network used by Cingular. Thus you can get much faster wireless data performance out of the phone than you would find with Cingular. Of course, the phone has yet to ship and so who knows when it will be available.