So I wasn't able to get this out of my mind and went to order 3 new 1200P panels today and actually backed out at the last moment after further consideration. I think it would drive me nuts to effectively have a 21.6" panel in 16:9 optimized content, which is everything. Which would bother me more than having the additional 10% viewspace for work. Especially considering I have 3 panels, plenty of workspace.

I think at this point in the market, I'm going to stick with 16:9 native resolutions. If I do any swaps, I'll probably try out dual 27" 4K panels (also 16:9, great for 1080P content), with one mounted below the other. That'll be pretty nice in time as 4K becomes better supported.

Agreed. I couldn't find (modern, thin bezel + Displayport) 1920x1200 panels when I was shopping last time. I do see a few on the market right now, when one of my 3 goes out, I'll sell off the other two and order three 1920x1200 panels for sure.