Hi Burr, I would definitely think that Rhino would be a more suitable companion, for a variety of reasons.

It's generally easier to share data back and forth between MoI and Rhino, for example you can copy and paste back and forth between them. Also they use the same native file format, there is probably just a higher degree of compatability at the file level.

There is more kind of common ground between MoI and Rhino with general operation since Rhino is basically like an older generation of MoI's UI. Even though Rhino is a lot more difficult to use than MoI, it will just generally have more in common with MoI than Amapi - Amapi evolved along a much different evolutionary line so to speak.

On top of that Rhino has a much more varied and deeper toolset than Amapi, so that also tends to make it a better companion as well.

Then on top of that like others have mentioned, Amapi development has actually been discontinued.

You'll certainly find that Rhino is a lot more complex and difficult to learn than MoI, but many of the modeling concepts that you learn in MoI will be applicable to be used in Rhino as well so in a certain sense MoI can be a good introduction to help you make more sense out of Rhino as well.

The only real thing I could see for Amapi would be if you want to do some polygon modeling instead of NURBS modeling, Amapi does have a nice set of tools for that.

- Michael