I have a 5K iMac and one of the new 13" macbook pros but working on both of them is a bit of a faff so I am considering binning the iMac in favour of the macbook in clamshell mode and dual 4lk monitors. I know this is possible but the question is how much it is likely to affect performance. I don't think I want the LG 4k Ultrafine because its only 21.5" which is pretty small all things considered. I don't want to get 4k screens and run them scaled at 1080 either because I currently have dual 1080 24" monitors and there isn't enough screen real estate for my liking and its not worth dropping probably the best part of £1000 on 2 new monitors to have the same resolution as before only sharper. People have been using various scaled resolutions to combat this but this obviously has a performance downside. I don't want to find that I have an OS that runs sluggishly if I run dual 27" 4k screens scaled to a weird res. Is there anyone out there (mainly web and app developers) who has tested the new 13" tbMBP with dual 4 monitors and if possible, people who have tested it with the various scaled resolutions. I like the look of the LG 27UD88 monitors and there are lots of reviews out there but none that I can find that are using two of them at once. What are peoples views on this?