I've thought about going with an iMac. Do you miss having a laptop for portability?? I have a MBP now but never take it anywhere.
I realised my macbook was on the desk all the time and left the house only once
I have an iPad and it's more than enough when I need something portable.
I made a list of all the reasons why I should change the laptop + external display combo for an iMac, maybe it will help you as well:
1. 250gb of storage vs 3TB of fusion drive - macbook's drive was constantly full and it became really annoying when I wanted to keep some files on the computer, like iTunes library, more photos, etc. I take a lot of pictures and they take a lot of space when in raw format, and then later even more as photoshop files.
2. 16GB vs 32GB of ram - although macbook pro is really fast, iMac is blazing
fast.
3. 1GB vs 2GB graphics - I play a lot in Batman Arkham games and had to turn down most of the graphic settings when on macbook - now have everything at MAX
4. Faster processor
5. For the past 8 months I was working on photos and design, 10, 12 hours a day and with the Thunderbolt Display I had to cover the window with a paper background so I wouldn't have any reflections on the screen, now I don't need to do anything, iMac's screen has almost no reflections.
I sold the display for £600 and macbook for £1000 and bought a second hand iMac on the very same day for £1550
I used gumtree to do that.
Hope that helps!