Bingowings said:

The monitor displays on the Death Star and within the elecrobinoculars have overlays.

I think the problem I have with your reasoning is the fact that Vader's screen is neither field equipment - where measurements/numbers etc would no doubt have some significance, nor is it used (within the movie in this instance at least) for information readouts. It's to give orders "face to face" and intimidate. That's not to say that off camera it isn't used for other things but that's not the point. What's important is the one scene the audience sees, and for this an uncluttered screen is sufficient from a film making perspective (and makes sense for all the reasons brought up) and doesn't go against the film's internal logic either.

I do really like the frame overlay and am in no way against an overlay of any kind. I can live with the text on the right. It's just the bit on the left I find intrusive.

Edit - Also, I've got to add - The Empire is an evil dictatorship. Vader and Palpatine are the evil overlords. Why would Vader need readouts when he's got terrified officers doing his bidding? May as well give him some paperwork to do as well :p