Hi Scribble! Sorry it's been a while.
In my humble opinion, I think the light's too bright. Your rank insignia look so realistic, but to my eyes (which aren't great, admittedly) the glare and shadow make them seem "off".
However, I have just noticed some sort of burnishing or pattern on the steel/silver parts that I hadn't seen before - it looks great!
I agree with @Cyfa, the materials and overall render are definitely realistic, but those glares are just too big and unnatural IMO.
Agreed that the glares are strong, but if you don't mind me explaining...
What I have here is that there are lights directly in the path of the reflection where those glares are. I was more playing with the "realism" of how the direct glare of the lights would play off of the shiny metal (bloom, glare, dispersion). I then saved the render as an OpenExr file and went in to bring out some of the details of the rest of the image in PS, basically just to adjust some of the exposure and cut back on some of the yellows of the brass.
In this next render, I've changed the HDRI environment light to something a little different. The last one I used basically had a black top and bottom (not that you would see the effects of the bottom) and all of the light was coming from the sides. With this one, the light is more evenly spread and you can see that there is a greyish metal surface rather than only highlights and shadows.
@Cyfa, thank you for noticing the secondary surface distinctions on the silver/chrome/nickel/whatever.
I'll rid this image of glares (or lessen those lights' intensities) if they're people think they don't belong after this render (also saved as OpenExr and adjusted slightly):

The only other thing I'm considering adjusting about the materials, themselves, is the brass...on the Roddenberry pins that I have, I've noticed that what I have here as brass is more like polished bronze, completely unlike the darkened bronze of the Commander Starfleet, upper Admirals, and the jacket insignia's delta (not seen here).