I have used the wireless hotspot feature off and on over the last year, never abused it but certainly had a few months in the 5GB range mostly from hotspot use. Never heard from Verizon and I do not pay for this feature.
Let's hang this one up right here. There's a difference between Mobile HotSpot(MHS) and wireless tethering(requires root). MHS is a paid service via Verizon, wireless tethering not so much. Verizon knows when you're using MHS because it's a service that verifies with their servers that you have the necessary package. Wireless tether reconfigures your wireless driver to accept incoming requests and essentially turns your phone into a mobile router. I just wanted to to put this out there for those that don't understand and may possibly think that MHS is a free service.