I've also had my RX-V750 for about a year, and have been totally happy with it. I have it in a pretty large room with a cathedral ceiling, and it does just fine in terms of volume. (My speakers are older DefTechs, efficiency is probably around 89 or 90 dB SPL - not inefficient, but not super-efficient either.) I probably don't crank movies as loud as some people, but I do crank 2-ch. music a lot. Either way, there's still plenty of "volume knob" to go, and the receiver doesn't run particularly hot, either.
I also sometimes have a little bit of regret at not springing for the extra dough to have gotten a 1500, but that's mostly just normal upgrade-envy. I don't actually think I'd hear much, if any, difference, at least not in my usage.
I thought that the auto-setup worked pretty well. I especially like the "Pure Direct" setting for 2-ch. music listening. Maybe some of my preference for Pure Direct is just in my head, but I can hear a difference.