I love mercurial but since I've gotten used to git I miss the lack of the staging area and stash in mercurial. I have to grudgingly admit they're very useful.

Yeah, when dvcs started becoming all the rage I tried mercurial first for some toy projects and really liked it. When I finally had to start using git I was absolutely baffled that it had won. I feel like git needs something that sits on top and does most the normal configuration and wraps the api. It reminds me of the problem with emacs, there is so much it’s just overwhelming to people.

Do you think mercurial has a better data model, or could git reach parity with just a better interface?

I think this point can be concisely summarized with:

  $ git help commit | wc -l
  506

  $ hg help commit | wc -l
  59

  $ hg help commit -v | wc -l
  96

Also, git currently has 169 subcommands by default, vs. mercurial's 50 (more available as extensions though).