Yes, complex editing operations on polysurfaces imported from MoI/Rhino to SpaceClaim using 3dm file format are possible. However, when I used to edit (e.g. did shelling) "free-form" kind of objects rather than mechanical one I usually ended up with invalid object when checking in Rhino.
I also disliked a concept of "active command" and user interface that puts big and small button icons together - it isn't clearly arranged.
But for changing a fillets, moving a face or other "simple" editing operations it was very very handy...

> user interface that puts big and small button icons
> together - it isn't clearly arranged.

This is going to become more common as more programs copy the Microsoft "Ribbon" style interface.

But the Ribbon was designed particularly for Microsoft Office. Some of the things like icons for Bold, Italic, Underline, etc... are so commonplace and pervasive that MS Office can get away with little icons for these things without really losing comprehension.

But I don't think that the same holds true for other applications.

- Michael