Hello And by "work" I don't mean by what Apple promises (I was burned by Apple with the GUI problems from 10.10). I need to streamline my home computing environment now that I am mainly working inside VMs via Virtualbox locally and via VPN. I'm deciding between a 5K iMac (with 64GB RAM and SSD, not that it should matter) or a 2014 to present 15 rMBP (16GB of ram and the dGPU). I'm specifically interested in knowing the limits of the two machines I mentioned. I have many static (txt docs, PDFs, latex docs, sublime text/IDE and iterm3) windows open all day (not to mention various VMs with the same workflow stuff and matlab) as well as several chrome canary windows open. My ideal would be going with the laptop (despite low RAM I have servers with much more that are easy enough to access) because I don't want a desktop workstation if and only if the 15 rMBP can handle two displays without getting the spin wheel of death and general lag when moving a window or doing some other banal action. If the 15 rMBP cannot handle two 4K's without hiccups, I'll go with a 5K iMac and 2 4K monitors. Despite the extra screen with the 5K iMac, I still prefer the laptop. Again, if and only if the laptop will be able to keep up with my workload. If it matters, I prefer to run at 1440 HiDPi rather than 1080 but if 1440 causes strain and 1080 does not, I can concede. But 60 Hz is a must. Finally, will I have any issues running a PCIe to 10 GbE adapter (this connects to my server and SSD RAID array). What is the recommended way to run this so there is no performance hit to neither the SSD RAID and the monitors? There is so much info on these forums a doubt the various displays and it's confusing since a lot of people are reporting problems from more than a year back, when MST, 30 Hz and 10.10's horrible software support for GUI. Things have gotten better and now I'd like to make a move. I have several Dell P2715Qs at work on other machines and other people have the P2415Q among many others. I have no brand loyalties, just prefer a good value which the Dell P2x15Q is. But are the problems reported in the mega thread still an issue on 10.11 and newer hardware? Other sub $1,000 options to consider that give me what I want? Thank you. Hopefully this thread helps many others and not just me.