Well with a 2D quad engine you'd be able to zoom in and out which would make for some quite useful effects (zooming in and out when the players get close to each other like in Loaded/Reloaded) on the PSX and as I said before you'd easily with one line of code be able to make the screen rotate and keep the player facing the same direction.
Are you thinking full models like Metal Gear Solid style from top view?
Are you thinking full models like Metal Gear Solid style from top view?