Just wondering which one of these combo's would give me more long term pleasure/value. I originally had leaned toward the 750 for the extra power, and because initially I will only be running a 5.1 setup. However, I may eventually want to go to a 7.1 configuration. I will be pushing 4 ohm polk audio lsi15's as mains, lsi9's as rears, and the room is approximately 16wx30lx10h. Anyone out there with similar experiences? What combo did you go with and why? The wife's trying to keep me as upgrade proof as possible, but I want the sound! Thanks in advance for any help.