of the modelers you listed:

I have to second the suggestion of C4D the core is a bit pricey compared to some of the others but it has one of the best modelers out there, and can be used for grouping your mesh which some other modelers don't tend to do as well, and includes bodypaint 3D a premier 3D paint program which also does great uv mapping.

I think Hexagon has one of the easiest interfaces and is a great modeling tool, it has basic 3D painting, and uv mapping. its drawback is in order to use it for grouping you have to split the mesh which I don't like to do. It's also the least expensive of the bunch you listed. (you can even get a version as well as a version of carrara by buying this book http://www.daz3d.com/i/shop/itemdetails/?item=9166

ZBrush is a great tool, but it isnt a particularly efficiant modeler. in order to get a decent polycount you need to fist sculpt your model and than draw a new topology over the top of that. Also you will need to go to an outside tool to uv map your models. but it has great painting and displacement tools, second to none.

Rhino is primarily a Nurbs modeler (though I believe they have added some poly tools with the latest version) Nurbs models do not convert to poly mesh very efficiently so its not an ideal tool for creating poser content, though there are some modelers who use it, I think it's going out of favor for the more poly based modelers.