Very stable and fast, complete solution for 3D modelling, rendering, texturing, sculpting, animation, scripting and compositing. It is a capable alternative to Autodesk 3ds Max or Maya.
Highlights: good integration with VectorWorks, ArchiCAD (all from Nemetschek), but also integration with After Effects, Unity (through FBX) and Photoshop (through multi-layered PSD exports).
The Physical render engine can lead to very believable lighting, with not too much grain. You can also do a hardware (GPU screen) rendering or integrate with RenderMan compliant renderers, if you want. That said, there is more than enough rendering power available as is.
The Motion Graphics (MoGraph) module is very flexible for procedural modelling and animation and so is the integrated visual scripting (called XPresso), the SDK (called Coffee for scripting), Character animation (Mocca) and even Python scripting support.
Flexible user interface, with multiple layouts you can save..
Runs on Windows and OSX and is fully capable of 64-bit memory access, GPU accelerated viewport display and multi-threaded rendering.
Complete file support and good workflow integration.
It has become free for students, but schools need to buy a maintenance license.
Very expensive if you need all functionality.
Y-axis is used for Upward direction (like most DCC software), which feels odd for CAD or BIM users.
Not as widely supported with books, resources and tutorials as 3ds Max or Maya. Good sources are Cineversity, Creative Cow and 3d fluff.
Very good and complete solution for rendering, animation and integration with CAD, BIM and presentations. Alternatives are 3ds Max (Windows-only) and Maya.
Very stable and reliable product. New features are welcomed (e.g. camera tracking in r16, the improved advanced rendering and the extensive Mograph and Character tools).