@arclight @benc Mercurial had a better UI, easier to learn for those coming from CVS and Subversion.
Linus designed git from the bottom up, exposing internal details and jargon at the UI level.
But... hg always felt sluggish to me, particularly on large repositories. That's probably why it won in the long term.
Had Mercurial been rewritten in C or C++ earlier, paying more attention to performance and scalability, it would have been the clear winner.