I have a friend who plays on a full hd monitor with a playstation 4. He pretty dedicated to console gaming, and is considering getting either a ps4 pro or xbox scoprio when they are released. Even though these consoles do not output native 4k often, its hard to dispute that the experience is substantial improved on a 4k screen. For him, something like this screen, or a follow up about a year from now, that costs between $250-$300 along with a mid gen console could be a great combination. 24 inches is a little small, but it is not as bad when you consider that most games are less than native 4k, and the smaller the screen, the less you notice upscalling artifacts.
For high end pc gaming, 1440p144hz is still the best around today. I absolutely love it.