Thanks, jkgsxr, that Crutchfield side-by-side comparison feature is handy! And, not to sound too much like a schizophrenic, indecisive shopper, I've (possibly) changed my mind yet again.
Rather than the refurb AVR-X11000W for $349 + shipping, Accessories4Less is offering a refurb DENON AVR-S900W with free shipping. (i.e. It would end up costing me an extra $20 or so for the S900W model.) The two models seem very similar, with the biggest difference, as far as I can tell, being that the S900W has "HDMI to HDMI Upconversion".
One question I had, though, was about the "Auto Speaker Calibration". The X1100W has "Audyssey MultEQ XT", while the S900W has "Audyssey MultEQ". What does the "XT" mean? Can someone translate this to English for a noob?