IXRTT is an abbr for Interexchange Radio Transmission Technologies. It's not Verizon per se but the std being developed to enable what's called 3G technologies.
Checked this several weeks ago and here is what I remember - I decided to not purchase either and went with regular cell phone America's Choice plan using MOK.
ExpressNet is a Verizon Internet service for speeds up to 144 Kbps
Broadband goes from 200-700 Kbps
Both these plans go for $79.99 /month 24/7 (last time I checked) or one can go with bandwidth purchase i.e. 20MB $39.99/mo or 60MB $59.99/month It requires a card that from Verizon runs $199.99 for 2 yr contract or $249.99 for 1 yr.
However, the broadband service is limited to about 30 cities at present time so useless unless ones travels are to these cities or reside there.