I really like Rhino 5. There was a big performance increase from Rhino v3 to v4, and there is big performance increase from v4 to v5 (there is also a 64 bit version of Rhino 5). Working with lots of layers and geometry is easy (including imported meshes from other apps). As already mentioned there are a number of plugins available to tailor and enhance Rhino. Including Neon a free fully raytraced viewport plug-in for Rhino 5.0.

MoI and Rhino 5 together are awesome!

"...Neon a free fully raytraced viewport plug-in for Rhino 5.0"

That is a pretty sexy combo. I went to youtube and watched this video: http://www.youtube.com/watch?v=JDm4xosy5IQ&feature=youtu.be.

Thanks for speaking up.....and probably making me spend the upgrade money :-P

What is the price of Neon ?

At this point Neon is free ... and it is a good tool .. it is slightly jumpy on my machines as it has to create a raytrace each time its moved ... so for most work I would rather use the display built in to MoI.
eric

It's pretty peppy on my new machine.

I also use MOI and Rhino together and have already upgraded to V5. I work with large mesh files (resulting from 3D scanning) and for me the 64bit version is worth every cent of the upgrade price.

Why MOI? I use it during the prototype stage of a project. I really like the speed with which I can create a concept model then dump it (via stl) to my 3D printer.