Phabricator was pretty nice overall I would say. The bug tracker in particular was good. I have to use Jira now and it's night and day.
The big flaw was there was essentially no CI support. That and the fact it was written in PHP, which you'd think wouldn't matter, but I did end up being forced to learn some PHP to fix Phabricator bugs and write custom linters.
Now we're using Gitlab which is also decent except it's written in Ruby which if anything is worse than PHP! Absolutely unreadable code base. I can't fix anything. (Except in gitlab-runner which is written in Go - I've contributed several fixes & features there.)