Go through the examples and see if they are:

• Functional
• Available in Qt Creator
• Documented
• Code quality is good
• Visual appearance is good

As far as what example we should have, I think it should look something like this to start with:

• View3D (current example polish)
• WASD Controller (polish)
• Dynamic Creation (currently part of simple)
• CustomMaterials (currently part of simple)
• PrincipaledMaterial (HDRI) (part of materials)
• Simple/HelloCube (Clean this up to be really simple)
• Picking (polish)
• Simple Editor (Studio Example)
• Blend Modes (polish)
• Shadows and Lighting (new)
• Qt Quick content in 3D (new)
• Fully custom material, preferably one that introduces how to create vertex shaders as well (new)