To use git you need to know clone, pull, commit, push. For larger projects branch and merge. Those fall into a lot of boxes that say "easy" or "elegant," and I really wouldn't hesitate to recommend git to a lot of projects, big or small, discounting specific needs, but I guess you've got some specific concerns that really don't translate well into simple statements.
I've used mercurial only to get some external requirements or tools going, and never used fossil. Could you elaborate a bit on why git is worse than either of them and why I should consider switching ?