I've been using Verizon Broadband Wireless on and off for about four years now. I always sign on when I travel, then cancel soon after because the service is so bad.
Verizon Broadband Wireless is not "scary fast." It's slow. Disconnects are frequent. Sometimes every few minutes. This was true with their PC card. It's true with their USB modem.
Only use it if you have to. I'm using it now, and I hate it.