Well, my 975 died and I have been facing the same question for quite some time now. In the mean time I have the XBox and Roku going directly to the TV and and OPPO directly plugged in to the amplifier and that works for me, for now.
I'm thinking that when I do make a move it'll be to upgrade rather than repair.
I did notice a significant difference when going from my old 970 to the 975 so I'm sure you'd notice a difference from the 990 to the 976.
Aperion Verus Grand Towers & Bookshelves, Verus Forte Center, Infinity Surrounds, Ultra-X12
Oppo BDP-203, XBOX360, Xbox One
LG 65" OLED
RR2150 w/Klipsch SCR-2