Since you own a receiver that can auto calibrate your system the SPL meter doesn't really add much. The Aperion would be fine as well you can get an SPL meter application for the Apple cell phone or ipad if you have on. That would be fine for basic calibration of speakers (not subwoofers) or checking loudness levels.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne