I've just started using it in my shop, and the tool is quite magical. A lot of work has gone into it, to the level where it will automatically search its own GitHub issues when crashes occur and provide relevant stackoverflows in a lot of cases. iOS provisioning specifically is horribly complicated, and the ad-hoc (pun intended) way my org was doing code signing before is archaic in comparison. Thanks Josh and the other Fastlane contributors for making such an awesome tool!