I'm behind the curve I realize, but I primarily use a 2012 15" MBP with the BTO 1680x1050 HR-AG screen. I have a 13" Retina(2015) as a back-up computer that I also keep set to 1680x1050.
The 13" is certainly a lot smaller, but I find it very useable at that resolution.
Of course 1680x1050 still isn't a ton of space. Right now, I don't have my Mac Pro(5,1) set up, but it's SO much more comfortable. I have a 27" Cinema on it as the primary display and a secondary 23" 1920x1200 Cinema. If not for lack of space I'd have had dual 27" displays. With doing all my grading and everything on line now, the more screen space the better. If I even physically had the space, I'd set up the 27" display now to use with my MBP. Don't forget that external displays, space permitting, are always an option.