Base 12 is more convenient than base 10. But that argument really only works if numbers were written in base 12. They're not, though, and that isn't changing any time soon. As a result, Imperial has to deal with two bases - the units themselves are defined base 12 (more or less; it's not really consistent e.g. with volume), but then you still have to do arithmetic in base 10.

So, until such time as we switch to base 12 for all numbers, metric is superior, because it is simpler.