The 7000 has suspension yah? The suspension would require that the top tube downwards so that it can be ridden and to increase clearance. The 7.1FX, 7.2FX have rigid forks which means the front of the frame won't be so high and the tube doesn't have to slope as much.
I just pulled up the images from Trek's website for the 2011 and 2012 7.2FX and put them on top of each other by resizing the browser Window. The red one is the 2011 and the black one is the 2012. They basically look the same to me.
