Having tested them all, Maya is THE modeler for Unity. Modeling is faster in maya 2010, and it has very powerful animation tools. All Maya content comes into Unity perfectly.
I would rate the unity mac modelers like this:
#1) Maya:
Pros: supported perfectly by Unity, and is cross-platform and does modeling, baking, and animation in one package. If someone on your team knows Mel, the possibilities are endless. No export to unity required.
Cons: Very expensive. Many of the plugins available do not work on the mac version.
Summary: Simply the best option if you can afford it. Yes, Autodesk is evil.
#2) Modo:
Pros: Modo is a very powerful modeler, with fast baking, including very good mesh-to-mesh normal map baking.
Cons: Costs $1K USD, has no character animation, and requires fbx export. Also has some issues with multiple UV sets when the scene uses multiple materials. Requires the team to use another package such as blender, cinema 4D, or Maya for character animation.
Summary: Excellent modeler that gets very fast with practice. With sticky keys, the workplane, the toolpipe and some practice, modo becomes more and more comfortable. The only down sides are the UV set bug, and lack of character animation, and by modo 501, it is likely that both of these issues will be long gone. Modo has stated they are interested in Unity, and have contacts there.
#3) Cinema 4D
Pros: All-in-one modeling and animation with a simple interface. Cross-platform. Lots of plugins.
Cons: Modeling in C4D is slow, and has strange behaviors like creating orphaned verts, which can cause real problems in games engines. I would not want to model in C4D. Some animations must be baked before they can be brought into Unity. There are frequent reports of missing polys, broken material asignments, and the C4D-to-Unity pipeline is just not as clean as it should be. Expensive for something that has Unity pipeline issues.
Summary: I am just not terribly impressed with this app. It's just so-so.
#4) Cheetah3D
Pros: Martin. Flawless Unity Support. Very affordable. Very minimal, native interface that is great for working on a notebook. Is multi-document like most other mac apps. Is under active development. Has basic modeling and character animation.
Cons: Primitive animation system that is still in it's infancy. Strange behaviors, some taken from Cinema 4D (orphaned verts), some from who knows where(deleting a vertex from the middle of an edge deletes the vertex, edge, and adjacent faces). Slow modeling workflow, without any selection tricks like maya 2010, modo, and silo have. Tedious baking that requires combining all objects in the scene because baking is per-object. Can't unwrap multiple meshes at once. Tools do not remain "live" while you tweak the parameters like in modo and maya. Doesn't support normal maps for baking or even displaying in the viewport, or even rendering. No mesh-to-mesh baking of any kind. No vertex painting or baking. I use vertex alpha and color all the time, even for the next gen consoles.
Summary: I like cheetah, and it has a lot of potential, but it's still just a renderer and exporter for me.
#5) Silo
Pros: Simply the fastest modeler ever. Light-weight. Like cheetah, it loads in one second from an SSD. Silo doesn't require jumping back and forth between tools constantly. I can insert edge loops and even slice up a mesh without ever leaving the transform tool. When you know the hot keys, you are flying. Modeling in silo just feels so natural and intelligent. If the developers had added FBX or Collada, better scene management, support for PSD textures and alpha channels, it would be a nice compliment to Unity.
Cons: Has the most basic materials system of any modeler I have ever seen. No FBX or Collada. No multiple UV sets. No character animation. Major display issues in snow leopard. Silo appears to be EOL, and nevercenter is now making iphone games, and silly photo-filter apps.
Summary: Silo was an app that seemed to have a bright future. The developers then lost interest and hired a PR person to poorly deal with the frustrated user community, and get as many sales as possible before retiring the app.
#6) Blender:
Pros: It's free, and has a thriving community. Modeling and character animation. 64-bit mac version.
Cons: Not so bad for noobs, but its hard for pros to adjust to all the blender weirdness. 2.5 is not finalized, and still no bmesh. Textures and diffuse color do not come into unity, making multiple materials on a single mesh a real problem. Textures must be manually assigned in the editor.
Summary: blender has lots of potential, and 2.5 is a huge improvement. I'll be watching blender more closely, but until texture assignments come across, it isn't worth my time to learn.
