I'll likely stick with my 500M for at least 3 more years. ...I use it for everything, PC, Xbox, PS & TV. The only thing I don't like about it is the heat it makes during the summer; and it's somewhat big & heavy, so moving it with me (in the backseat of my car) isn't fun.
I like the 1080p resolution, but since I sit about 5ft from it, it's not totally perfect for PC gaming. But I love the blacks, damn are they nice: the only time I'll upgrade to a new TV is when 4K gets good blacks/color/etc, & is at a reasonable price-point.