Director's 3D support is very nice -- it has a software renderer plus OpenGL rendering (Mac and Windows) and DirectX 5 and 7 rendering (Windows). And it runs fairly nicely in a web browser. There are also exporters for Maya, 3DS Max, and quite a lot of other high end tools to its proprietary w3d file format. But it's a lot more expensive than Blitz and it doesn't give you quite the raw performance Blitz does.