My Blu-ray player quit working; it also was used for playing my CDs. I am debating between the Sony 700 and 800/M2 model. My old player did not play SACDs. I want something that plays SACD (even though at the moment only have one SACD). I know both of these can handle SACD. I don't have any 4K Blu-ray disks at the moment but figure I might as well get that capability while I am at it. My speaker system is set up for 5.1 and the TV 4k. I see little difference between the 700 and 800/M2. With a Black Friday sale coming up, both are on sale but the 700 is cheaper by $70 Canadian (about $52 U.S.). I can afford to pay the little extra but do not really understand what I am benefitting by the 800 model.