After selling my old 2010 iMac, clearing out the space, I just received a 34" LG Ultrawide display to go with my 2014 13" MacBook Pro. The plan is to use it in clam-shell mode when I'm at home. The ultrawide display really works well for me, as you can have two applications open side by side in decent size. I'm still trying to figure out the best workflow with my new setup. Mostly working in Lightroom and just started to dive into Photoshop a little.
Down the road, I'm thinking maybe a mini to replace the rMBP, once it starts showing it's age.