It's not really conducive to making good art. It's extremely simple layout may appeal to some but for me, it just feels drab, like an office with no windows, or paintings, or a door. The design of 3D Builder is somewhat lacking.

I now use 3D builder on all my models to check for errors and to repair or ready them for the physical act of 3D printing. A little while ago Microsoft bought the Netfabb service that has helped them create a powerful set of repair tools for 3D models. While the actual design part of 3D builder leaves a lot to be desired the tools to edit models you have already made are in-depth and hugely helpful. In 3D printing, there are often times when you need to take an existing model and cut it, if your print bed is too small for the model, or reduce the complexity of the file, so it prints faster, or with fewer errors. While Tinkercad is great for designing basic 3D models it sometimes lacks in editing models that you already have. The designing workspace is well laid out with important tools in easy reach, things, like making holes and moving workplanes, become so important you need them right at the top all the time. It was the first program I used to make models and the primary colors stand out to me and make learning a little more fun. To combat this Tinkercad created generators that allows you to search for, and use, custom coded shapes that others have made. While there is a lot that can be done with primitives - primitives are simple shapes, squares and spheres and the like - there is a limit to the complexity of the shape you can create without being able to sculpt or edit specific parts.

Being a browser-based program, Tinkercad has some limitations to what it can do compared to a fully downloaded program.

Microsoft 3d builder