I've already decided I was gonna gloss Darth Vader and the helmet of the imperial guards.. But what about the stormies? They look pretty glossy themselves. Anyone else gloss theirs?

I did use gloss varnish on mine but really didn't like the look so brushed matt varnish after and it now has a semi-gloss sheen and looks a lot better.

I gloss everything but Vader's cape which I used a matte finish. For the troopers I did a gloss except for the blaster.

Look at screen caps from, in particular, RotJ. The troopers' armor is very shiny. I think gloss is the way to go, but to each their own.

I had no gloss on hand, so I used satin (which is in between matte and gloss). It's alright, and definitely looks shinier than matte, but I wonder if gloss would have been better. Maybe if you find the gloss too strong, satin is the way to go.

Its a personal preference. If you want pristine stormtroopers like fresh off parade ground go gloss, but if you want the battle scarred dirty look I think matte is better. I wouldnt do battle scarred and dirty with a gloss as that seems wrong, but I could see pristine with a matte finish.

You can layer the varnishes and get the expected result. If you put matt over gloss you will end up with a matt finish, given that a varnish is see through you wont upset any paint on the model.