Since you asked re: msysgit...

As a user of msysgit (CLI only), I find it quite stable in my daily use and am happy with it.  The issue has been raised in other forums that since it currently carries the "preview" label, it's perceived as "not stable for critical development needs" by some.  For my needs, I've found this to be absolutely false and the feedback usually comes from someone who hasn't yet tried it out and/or has other reasons for not wanting to move to Git.

On the bigger issue of Which DVCS, for Inkscape *users* rather than developers, I strongly believe it's a don't care red herring.

Pick the one that makes the most sense to enable your core contributors to collaborate, quickly get it implemented and begin using it.  While we *users* may prefer one over the other (probably the first one we tried), any of us that do want to actually start looking at the source are probably going to be able to quickly start using whatever one you choose with not a lot of drama.  The core cloning, pulling, and diffing aren't that different.

I started with Mercurial, liked it and still do, swore I'd never use Git and ironically find myself using msysgit/Github daily and liking it.  I've installed and uninstalled bzr too many times to count, but saw nothing to indicate I couldn't pick it up quickly and start running if interested.

Jon