It depends on what kind of applications and control you need. I can work on my own stuff at home very easily on a laptop because I have a fairly streamlined process. I can just tab between my terminal and text editor. I can't do that with my job, since I need probably 20 different programs running at once: multiple browser windows, debugger, specialized programs, chat window, email window, multiple text editors and guis... it's a major hassle on a laptop.

If I have to use Windows, I can't do it either. But give me virtual desktops, a tiling window manager and (sensibly laid out) keyboard shortcuts for everything, then I'll often even forget to use my second monitor.

Once the 15" retina display arrived, I instantly abandoned any notion of working on a desktop system. Far superior visuals than any big monitor I could afford, and I can work anywhere anytime.

I’m sure some people carry around those portable laptop stands that make it a little more ergonomic. A 15” screen isn’t too bad if you’re at a small table by yourself.