I never auditioned an MVP851, but the 861 audition I did 3 years ago led me to my 881BR. Definitely superior audio playback to anything else I'd listened to (including Denon, Cary and Marantz). Natural, warm and inviting. SACD playback is also superior as is the up-conversion of DVD to 1080. Very happy with my choice. Second Theo's recommendation to contact Audio Classics - they are the Mc pros.
Good luck & happy listening!
Good luck & happy listening!