I'm on my second build. I had bought an old Lethal Weapon 3 cabinet, the first build was a 37" 1080p television. Later someone gifted me a 40" 4K 120Hz Samsung TV so I rebuilt the whole thing. How could I pass up a free TV like that? For gaming, there are two display specs that apply: response time and input lag. Response time is a measurement of how long it takes for a pixel to change state, such as from black to white or red to blue. Input lag measures the delay it takes you to press a button or type a key and have the screen display the result.
A high response time causes ghosting and blurring, while a high input lag means waiting around for something to happen when a button is pressed. Of the two specs, the more critical for visual pinball is input lag; pressing a flipper button and having even a slight delay makes the game unplayable (and is in fact why some people have been turned off by visual pinball). TVs usually have higher input lag than monitors, but a TV with native 120Hz has half the input lag of a 60Hz monitor. A good input lag is anything less than 40ms, very good is less than 25ms, and less than 20ms is imperceptible. My TV has an input lag of 20ms in 120Hz mode. Response time isn't typically a deal-breaker, although watching the ghosting of the ball can be annoying. A good response time is less than 15ms; however, I haven't really noticed ghosting. The difference between 15ms and 20ms is very small.