i'm moving to brasil (from san francisco) in the summer (their winter) and am going to buy a new bike for my trip. i have always been a road bike guy (currently my baby is an 81 colnago with a full 2006 record group) but want to get a more versatile bike for brasil. my buddy down there is a big mountain biker and i'm a big road biker = buy a cross. i'm into the surly cross check (thinking of just buying one of their builds) but it seem that it is a little light on the low gears. is the lht better for my needs? can i ride mountain trails on it?

really what are the difference between the two? obviously i know the specs but what are the real world differences?

thanks fellas. happy riding.