If you're happy with the sound you have, I'd just keep the 7200.

Not only are you not hassling with all of the exchanging and shipping issues, but you keep two spare channels. These could be used for any number of applications you may discover such as if you decide to upgrade to a 6.1 or 7.1 setup, as a second zone pair, or even bi-amping your mains if you need (want) to do so one day.

Plus, all the stuff those guys said up above me.