* VcsCompare has benchmark statistics for repository size on a large variety of repositories, comparing Git, Mercurial and Bazaar
Ok, here's a link to my first super-generic and unspecial benchmarks comparing mercurial, git, and bzr.
Great! Real work instead of opinions! (but missing version info from hg & bzr)
To benchmark how they scale when number of revisions > 0 - real conversions are probably needed from kernel/gnome svn (slow and boring.. sorry)
And here's some from Mozilla's investigation into DSCM.
The benchmarks from Bazaar, comparing it to other DSCMs
These do not use any project history; caveat emptor. See https://lists.ubuntu.com/archives/bazaar/2008q1/039313.html for some benchmarks on the GNU Emacs repository.
The Benchmarks from Git, comparing it to other DSCM's
A small benchmark about tracking a home directory, which shows how similar are the performances of each of the tested DSCM (git/hg/bzr) without a clear winner and how much better they are compared to subversion: