"Softer" refers to the fact that the 981HD smooths out the image more, a by-product of the Faroudja chip. My experience with these players is mainly on a 32" display, which reduces the magnitude of the differences quite a bit.

As for SACD, the difference between 5.1 and 7.1 is something that I'm just starting to investigate (my beta sample didn't support 7.1 output of SACD). Keep in mind, though, that the 990 isn't a factor in this case - it isn't doing anything but bass management for SACD, because SACD is only delivered via multichannel analog (which isn't an input that can then have surround processing applied to it). The differences between the 981HD and 980H for DVD-A and SACD are subtle, but the 980H does have a bit of an edge because it uses a better DAC and simpler signal path than the 981HD.