@Michael
What I mean when I say its "pretty close" is that your environement map is good but I think you see too much "steps" in the gradients!
You should make two different metal looks, one non-blurred like chrome and one blurred but with non-visible "steps" , a smoother blur.

Here's two example from Auxpecker (all rights reserved)

First is a non-blurred chrome


Wich produce this kind of result



And here's the second example, anodized metal (could be also a 80% blurred metal) wich can be any color (or white for uncolored metal)


Wich produce this kind of result



As you see its two very different results, your environement map is between the two, its blurred but not enough maybe.
You said it was a 6 side cube image map but when I look at your screenshot it looks like different spot lights pointing at the model with not enough falloff, you can clearly see in the white part a circle shapes just like a circular gradient in photoshop but with not enough area between the dark and light colors. I hope you understand what I said :)
Can you share the image you are using? Or at least a screenshot of it?
Im annoying I know, always commenting and suggesting stuff :) Your tests are already looking very good Michael.