I have no idea other than to compare my 15 or so year old Yamaha RX-v990 5.1 receiver to my recently acquired Marantz PM8004. I have not A/B'd them but upstairs I love the Marantz in my 2 channel system (NHT SuperZeros, Marantz CD6004, Samsung N150P netbook for streaming IR) and the Yamaha as a 2 channel receiver downstairs (Celestion DL-8's, Onkyo CS5VL, Technic SL-QL1). They both sound great to me.
Home Theater: Yamaha RX-V990, Onkyo C-S5VL, Technics, SL-QL1, Celestion DL-8 Series II L/R, NHT center and rears
2-channel living room : Marantz PM8004, Marantz CD6004, Denon DP-23F, NHT SuperOnes
2-channel office: Marantz PM6004, NHT SuperOnes, internet radio fed by iPad Air