While everyone seems to be focusing on the issues of distractions, I have found myself in the habit of using one screen due to a particular testing issue. All

While everyone seems to be focusing on the issues of distractions, I have found myself in the habit of using one screen due to a particular testing issue. All of the devs in my group were using two screens, and so were the testers, but the majority of our customers used one screen. Customers would run into issues which the devs wouldn't be able to reproduce. It turned out that the issue was pop-ups ('foo is bar; click ok to continue') which would appear normally if you were running the app in your right-hand screen, but which would appear off-screen to a single-screen user. Being the only single-screen user in the development group enabled me to solve the bug and prevent many future cases of the same bug getting through into production.