Just out of curiosity, I'm running a 5.1 setup (fronts, center, sub and surrounds) - my question is - has anyone ever ran the 5.1 configuration with Fronts, Center, Sub and Rears ???? And does it make practical sense? Why or why not? I plan on going 6.1 or maybe 7.1 in another month or so, but I'm curious about the options while I'm still running 5.1.