I've started using pbranch extension for hg more seriously. It works nicely but is a little rough around the edges, in particular:
No hg qpop/push equivalent
I really miss this. I find myself constantly doing hg pgraph to figure out where I am and then typing the patch above or below.
No way to shelve a patch
With MQ, I can easily guard a patch to temporarily remove it from the queue. There doesn't seem to be a simple way to do that with pbranch.
Editing patch messages.
You use peditmessage, but because this modifies the repository, you then have to always hg pmerge -all. This pops to the top and causes a bunch of extra changesets, and it gets annoying quickly. And frustratingly, these patch messages do *not* appear in the repo history. So your code reviews of the main repo are just showered in useless merge messages, instead of the actual commit message you care about.
I don't know why, but there's no way to automatically commit a patch as a single changeset on the root default tip, then close the patch branch.
Inserting and deleting patches is horrible
Yuck - I really hope this gets easier soon.
Showing the current patch history
A little tip not mentioned on the pbranch site: the way to show the changelog history of the current patch is to do hg log -b patchname.