I'm gaming on a Sony S990a
, and I like it. It has an excellent input lag of around 18ms, and very good pic quality.
Of course there's some of caveats: it's a curved screen, which is a turn-off for a lot of people, even though the curve is pretty subtle in-person. Off-angle viewing isn't the best. The biggest issue is the backlighting is fairly uneven, mostly noticeable in a dark room during credits or black screens with title cards or logos, e.g. the Playstation logo when turning the PS4 on.
But IMO after tweaking it can achieve a good picture, even with backlight down low - nice colors and good black levels. And game mode is pretty much lag-free. Unfortunately, this model is rare unicorn when it comes to finding it in a store, so it's hard to see one for yourself to decide if any of the issues bother you or not.