I agree. I use the free version to noodle around, but I don't spend a lot of time on the models for a variety of reasons. I may be too used to the feature tree and rollbacks. Also, I am addicted to equations and variables for parametric designing. They have a cool app and I would pay $5 a month for it to be sure, but I am not going to spend $20 per month for it unless it nearly replaces f360, Solidworks, OpenSCAD, FreeCAD... I don't think it beats any of them right now.

TinkerCAD is on the iPad and actually fun to noodle with FYI.