I don't have personal experience with these specific bikes. But I know the components.
The 7.2's components are considerably better. The 8.2's shock is ungainly and will add unnecessary weight if you ride on relatively smooth roads. Doing 50 miles on a bike that's heavier, more sluggish, and less aerodynamic than its alternative would not be fun.

On an unrelated note: Are you by any chance, this guy?