[rco8786]

More of an individual developer preference, vs entire team's preference.

I prefer git, but my team opted for mercurial. Now(since we use kiln) I get to use git and my teammates can continue to use merc.

[rockhymas]

This makes it easier to bring on new team members who are more familiar with or comfortable with one DVCS.

And the (admittedly slight) gains in productivity for some of your developers is a nice bonus.