My wife rides a Trek 2.1 and I have a 7.5 fx, which have similar wheels and component quality. Theoretically, she should be faster because of the 2.1s road bike geometry, skinny tires and lower weight. (it really isn't that much of a weight difference) The reality is that she isn't faster, in fact I am faster riding the 7.5 fx and I can go for longer distances. The reason isn't related to the bike or the setup, but more the fact that I have been riding more and I work at getting faster/longer distances. I don't buy into the notion that a "road bike" will automatically make you faster.

The op can get faster with the 7.2 without spending much more than some barends and different tires, maybe some clipless pedals and shoes. I would stick a set of barends on your handlbar, flip the stem so the handlebar goes a little bit lower and get a pair of 28-32 lower weight slick tires. Cost to benefit ratio with these changes is fairly large. You may have to angle your saddle a little up when you lower your bars if there is too much pressure on your hands. If you feel that this helps and your distances are getting larger, you can invest in some clipless pedals and quality cycling shoes, which really do help on the hills.

Bottom line, you should work on the engine. Get yourself used to doing longer faster rides on your current bike.