As a big 3d fan (see my hunts ...), I am tickled by this. Great find @direwolf
Pros:
The power of a desktop CAD ... on a tablet. Really?? Didn't know that was possible. With zero lag? wow.
Moving edges is a cool feature.
Pencil-first is the right way of approaching this.
Can import images as a "foundation" or "reference" ... wonder how much the application can pre-build for you from a reference image ...

Cons:
Not sure if this is a con for the consumer but the leading desktop CAD manufacturers with their bloated CAD software may start to lose marketshare.