Despite having a small learning curve to understand how it works (mainly how designing on desktop viewport affects tablet and mobile), you can focus more on building great apps and less time creating professional websites. It makes me more productive.
Despite some glitches it is a worthwhile tool for making high-quality videos demoing or promoting mobile or macOS apps. I has only the features you need and no more! It was a pleasure to discovered it and I've been using it to promote UI Playground.
The Kanban visualisation of tasks really makes collaboration easier since we can understand at a glance what everyone is working and alignment is more straightforward.