I cut my cord last year, retaining only my high speed internet connection. Purchasing a sub for MLB.tv, I had to figure out a way to enable my home to continue to view the Red Sox. I found a program called "Hide My IP" that worked PERFECTLY!!!!!!!!!!! I would start my computer, ensure hidemyip was running and producing an overseas IP address (I tended to use London) and logged into the app to view the Sawx anytime I wanted. Once logged into the app, I was able to shut down the program and boost my speed. Occasionally, I'd run into problems, but 99% of the time, it was perfect.
And for an extra $10, I got all the AAA games, too. So I could watch the PawSox on occasion. For 2012, I'm thinking I may get the iPhone app for MLB.tv, but I know I won't be able to watch the Sox on the phone (location services will prevent that). But the above method will let me watch them at home.
We've save a pretty penny over what we were paying the cable company since we started this little program, and we rarely miss anything we want to watch. We subscribed to HULU+ (which is a gold mine) and Netflix (which we're considering dropping).
As for Comcast's bandwidth limit...we haven't come close. 250 GB is a lot, and we rarely go past 30 % each month, even when I'm on a downloading music spree.