Both the next gen consoles the PS4 and the Xbox One, use HDMI 1.4 as output. This means that a 4k monitor will be limited to 4k at 30 Hz, instead of 4k at 60 Hz. There are a lot of games that run at 60 FPS on the consoles, and so this option is out of the question, it will look awful. Even more so because a 4k monitor doesn't scale 1080 to 4k nearly as well as a TV would, it's night and day. 1440p is going to blur the 1080 signal it's receiving from the console(s), which means basically having a blur layer ontop of the entire image, and the result will be small details will be lost, and depending on how sensitive you are, you might notice this, and don't want to play the games you want to play, extreme example of course. Therefore, that leaves 1080, the best optimal resolution for the next gen consoles. However, which is better for you, between the 1440 and 1080? Nobody can answer that, we would have to know your viewing distance, display size (inches), as well as your visual acuity. So can't answer that one.