I too own the Vizio M3D550KD and I am seriously considering the 80" model in this series. I do want a bigger screen for my theater and I want it to be passive 3D as I prefer passive and all the projectors for the most part are active. If these sets provide the same performance as the M3D550KD its a great value as it provides deep blacks bright colors (10 bit not 8) and good video processing. I have a feeling i am going to have a Happy Birthday gift that is 80" wide! I Just wonder how the 70" XVT UHD sets will preform, might hold off for that instead.
Vizio 80" 3D LED M801D-A3 ISF Calibrated | Onkyo TX-NR818 w/ Polk Monitor 50 (Fronts), Onkyo SK-520 (Surronds), SKW-770 (Sub) | Win 8.1 PC i7 3930k, 2 SLI GeForce 770's, 32GB RAM | Mac Mini 2011 i5 2.3Ghz, 16 GB RAM w/ PLEX | Roku 3 | Oppo BDP-103D | Xbox One, PS4, Wii U, Xbox 360 S, PS3 Slim | Harmony Touch