My custom machine has a LCD in between the speakers in a standard height speaker panel (and standard size speakers), with an opening that is 6.5 x 13 inches, which is pretty much the biggest size you can fit. One game I run 96x196 (dots still look good at the size any higher resolution and they don't) and the other is 900x1800 so basically a cropped HD resolution. Would not surprise me to see Stern doing something similar. This is also similar to what DP did, but their screen was wider, not sure what the new width/ratio is.
One reason I moved to the larger screens, after first doing color at the standard 32x128, was it does make doing animations much easier. Trying to take an animation down to 32x128 is extremely hard to make it look good (as we have certainly seen with movie clips in stern games). Much easier to get a good looking animation on 96x196 and obviously the 900x1800 requires no real change in sizing.