Is three.js good for 3D in web pages?

Question

Have you got experience with three.js?
If yes, could you tell:
- Is three.js a good tool for embedding 3D content in web page?
- Does three.js create good-quality 3D content?
- Is three.js easy to learn?
- Is three.js easy to use?
- Is there a better tool for embedding 3D content in web page?