[BlackFly]

> If you ever change machine or do pair programming or whatever where you are not using your highly-tweaked config, and you are essentially a frustrated jibbering wreck

Not really, for much of the same reasons that I don't lose it when I visit a friend's house and find they stored their utensils in a different location relative to the sink: it is obvious that someone will set things up differently.

Ever help a friend, who being French, has an azerty keyboard? Defaults are also contextual and this is but one example. Heck if you are a windows/linux/mac user who occassionally helps people on another OS you will experience the difference in defaults. Being a touch typer, it was weird the first few times, but it is amazing at how quickly you learn to touch type on an azerty with just helping a friend. I even managed to help people with qwerty keyboards who insisted on using dvorak layouts.

So I don't find your argument for defaults convincing because I find my environment to be already more heterogeneous with respect to defaults than you seem to and modifying configuration is the only way to achieve some level of homogeneity for my own use.