My commuter is nominally a CX bike (entry-level Kona Jake). It will likely never see off-road use, and I do use it as my road bike on rainy days. I have an older Jake and used to have a Cross Check that each got used as my fair weather road bike for a while, but I also used both of them off road at other times. Now I've got two "pure" road bikes. The ability to put fat tires on the CX bikes makes them a nice option for rides with bad pavement, but there's something about railing a corner on a road bike that just feels right.
That TriCross looks pretty sweet, but you really should break out the knobbies and let it live the dream. You might have to drive an hour or so to get to a CX race, but it's worth the effort.