Oh, Outlaw actually said that the 970 is a 1070 minus the amps. And the 990 is the size that it is because it is based on an existing platform (the Sherwood P-965), which is a platform that was developed as a receiver initially (the Sherwood R-965). The chassis size was dictated by the need for seven amp channels - the P-965 just left the sides of the rear panel empty when the amp channels went away, but the 990 used those areas to fit in the balanced outputs and DVI connections.