I frequent TCU's fan site 3 or 4 times a week.
Their address is
http://www.killerfrogs.com/msgboard/
I think their board is a bit more active in the sense that they have a few more threads, on average, created each day. However, I think the number of people that frequent that board is about the same number that pass through this board on a daily basis.
I've noticed that the TCU fans are quite passionate about their Horned Frogs (as one would expect) and they talk alot about football in the state of Texas. However, I have noticed that they lack a very good working knowledge of the MWC. For example, they are unfamiliar with the different facilities at each school, and the overall tradition of each school. I suppose this should be expected as they have only been in the conference for a few years.