It has been said, that the Ultimate Shoot Em Up systems are Saturn & PCE. They’re not.
I'd say the shooter "argument" is dead there allready.. saturn has radient silvergun and dodonpatchi.. both are THE benchmark shot'em'ups in my book.
If we do stick to the 16bit era/argument.. well the 25fps /50hz "issue" is pretty much as stupid as the "snes has a slow cpu" or "megadrive can't show shit but atari colours"..
So what's left is just the one who had the best games.. and that was the X6800.. probably followed by PCE
megadrive gets saved by thundercross and gunstar..
Snes has it's r-type 3..
Amiga well.. battlesquadron and Swiv