I still use ST emulation for a few games. If I dont have my 1200 at hand I often play the ST versions of games under emu simply because they run a little better on my GP2x.
Paradroid 90 is a little more forgiving under ST emulation, it can be frustratingly hard on miggy - so much so I still have a joystick with teeth marks in it. On ST I tend to be able to use cover a little easier in shoot outs and enemy droids who rely on visual detection dont see me all the time.
I often wondered which machine it was origionaly written for as the vertical only scrolling is very ST.