I think I'd be quickly frustrated though because even on a 16" MBP, using an IDE like Xcode or Android Studio the screen gets jam-packed so easily with all the panes and inspectors and such. That screen size is probably like a football field to the vim/emacs types though.
I do webdev in Vim. It is nice to have the browser on one side and the editor on the other. With a pretty standard 1080p 24" monitor, that is just barely doable with a comfy font size. My coworkers often write very longgg lines of code :/
I removed armrests because my wrists are resting at the side of the touchpad. I never touched the armrest unless I was standing up or sitting down.
Similarly I resent the loss of 16:10 or taller monitors — I want those extra few lines of context.
Now, there was a time long long ago when I could work with a single 80x24 screen. But then I had a huge L-shaped desk with one printed listing for the current primary code file, one for its interfaces (header file), one for its unit tests (who am I kidding), one for documentation.
These days I have a 14 inch macbook, which I put on top of a few books and control with a keyboard + magic trackpad. Can't say it's made me any more or less productive.
The biggest improvement i've made was acquiring a desk treadmill, hasn't affected my productivity but now I'm getting 10-20k steps a day without really thinking much about it.