I use quilt a lot for development. Currently, If I had to choose between BK and quilt – I’d choose quilt.
I use bzr in other development projects like MemberDB. I use git as a frontend for SVN (it is *so* much faster than the svn client and incredibly more space efficient… A copy of the entire history of a tree stored in git is usually less than a single svn checkout). I also use darcs (and quilt) for offlineimap and just about every other revision control tool at some point.
So this is a bit of a discussion about how I work and how bzr-loom would help it… (I’ve wished for a long time that bk had stuff like this… bk collapse is just not what I want, although others use it lots).
The loom plugin to bzr looks like a fantasy world of goodness where the revision control system has some knowledge of these work in progress patches. The ability to push and pull looms around the place seems awfully nice.
What’s even more awsome is that you can push your set of patches up to a normal bzr branch and they become normal commits! i.e. you get rid of the whole “convert quilt patches into changesets” pain and just push.
Revision tracking them (so you can see what you’ve changed in your patch set) is also nice (I have thought about keeping patches/ in a bzr repo for this purpose). So I can now get a history of my patchset against various mainline versions.
One of the big advantages of quilt is speed – it’s lightning fast (basically being a diff and patch wrapper) . Hopefully bzr looms continue in this fine tradition (and I wish other systems would get something like it too)