I have used this on the linux side using the text commands mainly to pull stuff down from .git servers. Are you using this under windows? Is there a gui client? Most of my users probably would not like the complexity that the text clients have to offer.
It's quite more mature than I expected it. And even if you don't use the shell extension, it's probably the fastest and easiest way to get a working command-line Mercurial environment under Windows. (well, command line plus useful tools like qct; which is the way I use it on Linux)
I used Subversion for a year or two. Then I tried git... and it seemed confusing. Mercurial is the one that made me understand (and love) the DVCS concepts. The support for branching and merging is a bit like moving from CVS to SVN and noticing the repository-wide revision number: once you switch, you can't look back.
Me too, I voted for it but it still does not appear in the list. I've used other systems in the past including perforce(which is awful) and like CVS for its simplicity to set up and use on both UNIX and Windows.
Yes, absurd isn't it? It must be one of the best-known source code control systems in existence, although it is getting a bit long in the tooth. Anyway, I use it, although I think I would switch to Subversion if I didn't have so much time invested in it.
We are still using CVS served on a linux server. I started using it on a project in the 90s and the repository has grown from then to include the 500K+ lines of my code + 1 to 2 times that amount of other users code. The main reason not to move to subversion is that we really like the client application on windows (wincvs). Since rapidsvn is improving I am willing to give subversion a look especially because we need to move to a server that is not hosted on our network (too hard/expensive to get firewall exceptions/DMZ in our hospital) so a user can access the server remotely.