does anyone know if the superior version in this case is DOS or AMIGA? or AMIGA CD32?

I didn't even know there WAS an Amiga version. Am I right in thinking around this time DOS games began to close the gaps with Amiga games in terms of visuals? I know for years the Amiga version was just "better" than the DOS version of the same game...

PC version has textures, amiga version has only vector based world.

Amiga also does not have the expansion pack... I believe that it also does not have the animated cut scenes after missions, etc. DOS version of SubWar is better in this case.

I'm guessing the Amiga probably looks nicer, but apparently as people mention below, the DOS version has more content included.

So it's ultimately up to you.

Amiga version doesn't look better. As Aquarium78 wrote, PC version is textured so gfx on PC is more advanced

Also avionic like sonar is pretty dumbed down on amiga version. Whem I had A1200 I quite enjoyed playing it but PC version is simply better.