I've used all types of setups from triple 24" and dual 27" monitors, and every laptop from 11" up to 17" In the end, I'm most productive on a 15" macbook at 19

I've used all types of setups from triple 24" and dual 27" monitors, and every laptop from 11" up to 17" In the end, I'm most productive on a 15" macbook at 1920x1200 resolution, the main reasons are: 0. I have my full perfect environment with me at all times, there is no switching between laptop/desktop etc. This is huge. 1. It's small and light enough that I can carry it around everywhere (unlike 17") - increasing productivity by a lot. 2. I'm forced to use the keyboard more which exercises the muscle memory so I switch much faster to any window in the current state without thinking about it. 3. My head doesn't need to move from one screen to another, this action is more expensive than an instant alt tab. 4. I found that the best work gets done in certain "focus scopes". Adding more windows/screens to this as you say "logs, command line, and editor all visible, and ideally a browser too" - leads to unnecessary visual data - since you can't process all those windows simultaneously anyway. The 15" has just enough room to comfortably fit the necessities for each one I use: a) 2 side by side editor @ 80 chars + file tree b) a browser window + debug tools c) terminal sessions with up to 8 panes d) a combination of browser / editor / terminal The one exception is when needing to run background tasks which output logs - which you want to 'keep an eye' on - for this I found a vertical monitor on the side is helpful - although in the end replicated it by putting the terminals to the bottom right/left of the screen beside the dock - that way I can see the output, but they are not distracting.