I have to constantly look up US imperial amounts. I like that the imperial system is sometimes based on twelves, the problem is where it isn't (volume is based on doubling, inches are successive halving). It's really easy to divide things into halves, quarters, and thirds in imperial, where in the metric system you have to round.

Honestly, a system completely standardized around twelves or sixties would be near optimal.

I forget where I first saw the idea, but I have adopted it as my own: the really sane thing for the French revolutionaries to have done would have been to switch to a duodecimal ('dozenal') counting system, not to base things on ten (which is a really terrible number).