Watch out for Rhino. It's export is not always clean and can leave holes. I spend a lot of time cleaning up Rhino and MAX models. Max is painfully overwritten and requires too many plug ins to make it really useful out of the box. If you are looking to build malable poly surfaces, Mirai is the best I have used. It is high-end and expensive but MAX, Lightwave, Soft and Maya have gone to some length to copy syuff from Mirai. (quite little trips to Viewpoint, you know fact finding....) Nendo is alot like Mirai, not as elegant but very fast. almost no learning curve and under a 100 bucks.