I've thought about switching because when you watch most of the non-TDF races they use the metric system and I'd like to have a better feel for what those speeds and distances really mean. But do I really want to have a better understanding of how fast they're going? I feel slow enough already.

The one good thing about the imperial stuff is that 100 miles is more manly than 100 km. The next time you're on mile 99 of a century and that last mile seems so important, think about what it would feel like if you were using the metric system. Would you really care about the difference between 159 and 161 km? Funny how those arbitrary units have such an influence, isn't it?