Default wireframe mode, very fast, no depth sorting, ideal to work. All real time rotations are done in this mode.
Quickdraw3D wireframe renderer. This mode is quite fast too.
Once the view has been set-up properly, you can switch to the interactive renderer (Gouraud Shading; no shadows or reflections, transparencies, or antialiasing). Frames are usually drawn within seconds.
Quickdraw3D supports external renderers, such as the one sold by LightWorks Design. It is a Phong renderer that allows shadows, transparencies and antialiasing (smoother image). Rendering times are about 10 times slower than with the interactive renderer, but nicer. You can switch to this renderer for final rendering.
If you want even nicer images, you can export an exact view as a POV-Ray scene description. POV-Ray is a free ray-tracer, which can render very high quality scenes with shadows, transparencies, reflections and refractions. Of course, this beauty comes at a price: rendering time...