I broke my laptop screen and was forced to rethink my IT setup. For the first time in 10 years, I went back to a desktop as my main computer: the 27" iMac and will fix up my laptop as a secondary computer for onsite client work or travel. My desktop is also connected to one additional large Thunderbolt display.
The difference between the 5k monitor and the Thunderbolt screen is amazing. After working for 1 day on the new screen, you can't imagine having had to deal with this grainy Thunderbolt monitor for a couple of years. (The Thunderbolt screen is long overdue for an upgrade).
Two big monitors work also better than one big screen and a laptop as a side monitor. Mac OSX is still clunky when dragging large application windows between different size screens. You always had to fiddle and resize windows. Now that the monitors are more or less the same aspect ratio I no longer have that issue.
Still I believe that the fluid window-based operating system where you can resize and position windows where ever you want them creates messy work environments. Mac OSX needs some sort of grid structure where you can snap things into place. Maybe an extension of the new multi-app feature that is now part of iOS.
When going back to desktop you need to budget for one more piece of equipment: a backup battery (UPS). The power goes down, your computer goes down. Apple should have put in a 5 minute battery that enables you to power down the machine orderly in case of a power failure. The latter we tend to have here in Israel in the middle of the summer when air conditioners drive the power grid to its maximum capacity, or in the winter when violent thunderstorms hit power lines.