We've switched to Phabricator and lived in it for a few weeks. As part of our sprint process, we needed a way to track what tasks go on a sprint, so we've tried both creating a "Sprint X" project as well as using Workboards and creating a "Sprint X" column (I'm not clear on which is better - it looks like there are open tasks for further supporting "milestones" using both approaches).
Nevertheless, aside from the auto-re-prioritization-on-drag-and-drop bug, the latter works mostly fine, with one exception: testing/verification. Specifically, once we finish a sprint and push everything to our staging environment, we need to have QA go through the list of completed tasks for that sprint to verify them. To do this, we need at least one of the following:
(1) [probably most approprate] a way to view closed bugs on a workboard (right now they just disappear from the workboard which makes it impossible to view completed items on a given milestone).
(2) a way to search for bugs, open or closed, in a given workboard column (this is more annoying but it's a fine stop-gap solution).
(3) if all else fails, a new status called "Testing" that we can mark things as instead of "Resolved", so that when a developer finished, they mark it as "Testing", then when the tester validates, it can be marked as "Resolved". Not my ideal choice but it would do the job and I know other companies do this (and in fact Pivotal's additional statuses do this sort of thing).
In the meantime, if you know of any hack or workaround we can use to meet the above use case using workboards, let us know.