I use MOI for fixing a lot of geometry outside of a CAD system. I like the way it functions etc. I've dabbled in rhino and considered buying it, but it does have an awesome feature where you draw a grid out and it projects it onto the surface and gives you a fresh clean surface. I suppose it's a little like projecting curves onto a surface and then using a sweep or whatever, but it cuts out the faffing with rebuilding afterwards.

I know nothing about programming and also not trying to compare the two programs. I may be well off the mark here, might be something that no one uses I don't know. Just throwing it out there :-)