If it was sheerly on brand I'd go with the Onkyo. But as they are at stores, go and take a listen to each display - maybe take one of your favorite action movies along or something or a CD, so you can hear the same part of a movie or music on each system.

Always found that Bestbuy is way over priced, so if you like the system there - see if you can find it on Amazon or somewhere online cheaper!