I see a lot of programmers (and, generally, tech people) using the old "Classic theme" in Windows instead of Aero (or Luna in Windows XP) for reasons like "it is faster" or "I don't want eye-candy".
However, most non-programmer users will have the default theme enabled, so these programmers will work (and, possibly, design and debug its application) in a non-standard environment (unless they are targeting Windows Server).
For example, a programmer that never uses Aero, may not even know that hovering a button gives it a "halo" effect.
So, should programmers try to have their workstation configuration as closest as possible to the real world, or should they rely on something/someone else (test team, UI design team, etc.) for this "real world integration"? And what if the programmer is working as a one-man-team (being designer, coder and tester)?