I am user of Softimage XSI mainly a Subdivision application(talking only about modelling) but i also used NURBS in testing Alias Studio, i also modeled in Rhino 1.0 and 2.0 and SOLID modeling in Solidworks besides Polygon arch work in 3dsMax.
I am user that usually finds software not very friendly- except Sketchup but it is very limited for Design work . In my case i hate that XSI and all other Subdivision modellers are so dependent on topology and that there is no way to "fix" some control points/edges despite SubD degree. In Nurbs i hate that they cant be flexible enough and that i just cant move things around and that is too much work compared with SubD to get a General form.
My opinion is that the Nurbs only for conceptual work is not the way to go. Catia for example has http://www.3ds.com/flashgallery/imagine-and-shape-v5r17/ that shows some promise, of course they are in a 20000$ app but it shows a way. This also reminds of an app like PTC Pro Concept that was buggy but it was more flexible.



Neverthless this is what i like and dislike about MOI- i didnt spent more than 30 min with it.

+ Interface is aestetical pleasing
+ all commands are at hand
+screen size isnt wasted in toolbars or in useless bars that has only the application name.

- Screen rotation/dolly is slower than in XSI ( i am in a Mobility Radeon 9700)- seems improved over August release.
- Screen commands dont are productivity friendly.
- Filleting not always works with me. I found that latter that one of the problems was that i was mistaken and was also selecting the lines i designed to extrude. But the problem still persists when i change some measure.