Steve Berry reports his Verizon 4G wireless works as advertised when he's in a 4G coverage area, but that the problem is that his commute takes him into 3G territory and that's a problem:
When the 4G signal is low and a 3G is available, the device switches modes. This drops the existing connection and 3G takes 20-30 seconds to activate. If you happen to come back into a 4G area (signal level above the 3G value), it switches modes again taking another 30 seconds to establish an active link. In the 1 hour Worcester to Boston route, I used to lose 3G connectivity twice and lose about 2 minutes while the SSLVPN and MiFi resynchronized. Since moving to the 4G, I lose 30 minutes of the 1 hour commute due to continuous mode changes.
There is no ability to force the unit into 3G or 4G only mode. There is no standard for setting up a new connection before dropping an existing connection.