I organized the migration from CVS -> Mercurial at my last job, and finally after several years when it became clear Git was where industry was headed we switched from Mercurial -> Git. After resisting it for a long time and then being forced to use it for a collaborative project with another firm, I have to say git is way better at being a DVCS than Mercurial.

I think, as other have mentioned, that once you truly "grok" git you begin to understand the elegance and simplicity of the system and how its layered. Ultimately git's use of branch pointers was a way better solution than encoding branch data in the commit itself. To it's credit Mercurial did attempt to rectify this later with bookmarks, but ultimately DVCSs are about branch management, and git has always excelled at it.