To me, the 7.2 seemed like it was a better value than most other bike's in its price range by a large margin. The 7.3, not as much. I've been riding a 7.2 pretty hard for the last several months without major issue - some of the 7.1's parts, as mentioned above, arn't as durable and/or comfortable over long distances.

As of last winter when I was shopping, it seemed like alot of Bikeforum posters preferred the 7.3, but if you are coming off of an Expidition I'd say save the money ($100 or so, right?) and customize specifically what you want to improve as you become used to the new style of riding.