Phabricator is also pretty amusing in terms of UX (by default), which is helpful when dealing with things that tend to anger folks -- like spirited reviews. I've often wondered if the sense of humor is half fun, half intentional in terms of psychologically making tedious work better for all involved. Even if accidental it's a nice thought.

Based on my experience, Phabricator has some quirks but is quite solid, and the well-designed command line arc workflow would please folks who refuse to open a Web browser.