Three of us have been using git with a shared (git) repository on a server. We've been pushing and pulling to/from the shared repository as opposed to peer-to-peer just as a matter of convenience and familiarity.
I have to say I like the concept of distibuted version control, or more to the point: versioning locally, pushing, and pulling. This is the first I've used such a tool. Mostly I've been using svn for the last few years. We've not tried the svn/git combo pack, just because we did not need or want to use svn in this case.
I also have to say after a couple two three weeks of using git, I am not crazy about git per se. Aside from just the learning adjustment that this is not svn and this is distributed version control, the adjustment and learning about what I would call the "quirks" of git have been somewhat discouraging.
I'd compare some of the cryptic language of git to some of the cryptic error messages a programmer new to erlang sees, or haskell / complexly type inferred languages. Combined with a vocabulary only a kernel linux hacker could appreciate, I suppose. I don't think this language is due to the concepts of distributed version control per se, rather to git's implementation and implementors.
So git seems to be winning. I've not tried mercurial or other distributed repositories. Is git so good? Or just the one that's winning for reasons other than usability? And stuff.