which mercurial version to use??

[Leo Razoumov]

Hi Experts,
I have been using Mercurial 0.9.3 for a about a month for several
projects at home and at work and I love it!! (I am former CVS and
current Perforce user as well).
Browsing through Hg mailing lists and  Developers pages in Mercurial
Wiki I noticed several Hg repos that contain bug fixes and new
features:

http://selenic.com/repo/hg
http://selenic.com/repo/hg-stable

Is it save to upgrade from hg-0.9.3 to the tip of "hg" or "hg-stable"
repo without running a risk of corrupting my project repos or screwing
my ongoing work?

In general, how stable is "hg-stable"??

Thanks,
--Leo--