The software is great. It's easy to use, feature rich. The software is polished and mostly bug free. Their autosave and syncing features are definitely among the best I have seen. It has great export options and the history based mdoelling is exactly the UX you want out of a tool like this.

- it is easy to use - on iPad it feels like natural designing - very smart learning curve via embedded tutorials

The parameterization of the work and the time saved.