The best way to find out how a normal person drives a car is to put a normal person in the drivers seat. Watching usertesting.com videos has shown me how cluttered and slow a normal person's computer can be. It also showed me the interesting ways those people interact with their clunkers.

Instead of having a second crippled computer for testing, I would rather use tools like Charles (http://www.charlesproxy.com/) to cripple my computer in a tweakable and consistent way.

This way I can develop, optimize for certain controlled conditions on the same machine, and verify my optimizations with real people.