I just bought a 7200 and am enjoying it very much. Based on your description, I think a 7100 would be just fine though.
It seems to me that the 7200FX is more like a road bike, with the handlebars placed more forward to get you in a more aerodynamic position. This may be better for longer rides, worse for commuting. Also, no front suspension fork on the FX. Probably not a big deal, not sure how much non-paved riding you will be doing.