Branching in Mercurial is as good as or better than in git, but it takes a few minutes of additional reading until the full flexibility of Mercurial's model actually reveals itself. Revisions can be safely ignored in favor of commit hashes. I haven't used revision numbers in hg for at least a decade now. And hg has a stash implementation that is on par with every other VCS that I've used so far.

TortoiseHG is a very good client that covers all common Mercurial operations and then some. It's on par with a couple of commercial git clients that I've used. On the server side, there's e.g. heptapod as a GitLab fork that has a deep Mercurial implementation.