The 990's component and DVI inputs are assignable; the 970's component and DVI inputs are permanently assigned to specific inputs. The 990's video input labels can be edited (so "Video1" becomes "Cable"). The 990 apparently has beefier DAC's, which will likely help on two-channel listening. The 990 has a phono input, auto-setup (channel distances, levels, and speaker sizes; no EQ), an independent second zone, upsampling of stereo sources, USB input, two-way control through the RS-232 port (970's RS-232 port is apparently solely there for firmware updates), balanced pre-amp outputs, and a couple extra inputs. It also comes in a much larger chassis, of course, which could be considered a benefit for the 970. The 970 also has the updated version of the 950's analog bass management switch for the 7.1 direct input (allowing full bypass, analog 80Hz crossover, or digital bass management); the 990 doesn't offer that.