The main navigation bar is simple and very clear, it's easy to find the most important sections (schema/model/media).
I like the preview image of each model/component. It makes it very easy to find the right components when editing content.
Finding content or certain pages is really easy, because the filters make sense.
As a developer I really liked that API returns clean, flat data structures.
Support is good: the prepr team is directly reachable via Slack and responds quickly.