I don't own a BLT, but I've done a lot of research. The nice thing about Bruce Gordons bikes is that they all have the same frame. The BLT would probably be fine for light off road touring. If you go to Sheldon Brown's web site, he has some great info:
www.sheldonbrown.com
His take is that tires (and wheels) actually have more of an impact on ride quality than any other factor. Tires are a relatively inexpensive why to have a huge impact on ride quality and durability. The BLT would probably work fine for what your intent is, and if you want to use it on rougher terrain, you can consider getting a more durable tire.
