Super easy to learn. We started using Shapr3D for a 3D prototyping unit in an architecture school - easy and students could use it quickly, better for 3D printing than the modeling programs they are currently using. I was able to teach my 7th grader in about 2-3 hours. Easy to transition from desktop to iPad.
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 modeling is exactly the UX you want out of a tool like this.