I got the COMCAST USB adapter, the so called XI2go or Comcast internet to go 3 months ago. The service literally sucks.
You have to run a program, XFINITY, to activate the comcast USB adapter and connect to internet. That is not so unusual. The problem is that this program is constantly freezing. Everytime the screen goes to sleep the program stops and I have to constantly Ctr+Alt+Del to open the task manager, kill the XFINITY manager and restart it again.
It is slow to connect to internet, sometimes it takes 1 minute, when a simple USB WiFi adapter does it in seconds.
If that was not enough when I tried to cancel the service I was told that there was an early termination fee of $150, which the representative that sold me the service over the phone failed to tell me.