Well for maya Nurbs is the way to go, as nurbs is the main thing for maya.

Polys were added later for maya so polys won't be up to the same standard as nurbs in maya, not sure about sub-divs.

I've came from 3D studio max and maya doesn't seem to have any patch modeling in it well compared to 3D studio 2 different programs, that work in different ways.

Nurbs in maya is way way better than 3D studio max it seems to be much more flexiable in maya than 3D studio max, so in maya at least you'd be best to use nurbs to get your object sorted then use polys or sub-div to sort out any detail problems you might have then output the object how ever you want or need to after that.

Nurbs don't have vertex that's a part of poly modeling nurbs is based purely upon comlex maths, and that's why you'll get prefect cruves and smoother surfaces for a object where as in polys you are dealing with each and every face as a seprate item.

When you render out a nurbs object the render turns it into a poly then renders out the poly, the differeance is that the mesh will have much smaller faces thus you get a smoother looking object in the render.

The nurbs objects will be a 1 piece item not in parts so the different parts are welded together rather than left apart, this will be done so that the animators can move the objects without them falling apart all the time.

Nurbs will take longer to manage on a slower computer and render slower but it depends on what your doing, movie studios shell out heaps of cash to buy render farms and to get the right programs so they can do what they need.

Processing power isn't an issuse for them because they can simply go and buy more if they really need it, also movies need really detailed objects so they look right in the movie looking at toy story 1 and you will see textures are streached here and there.

If you look at yoda from esp 2 in star wars you won't see textures streaching and he looks real instead of plastic looking.

Shrek 1 and 2 have kept the plastic type look but you don't get any textures streaching.

In final fantasy the movie the girl was rendered in 2 parts the girls face and body was 1 part and the hair all 10,000 trands of it was rendered seprately and then added in later.

The final fantasy movie is what setup maya as a movie object/render program, as maya was made specially for this movie versions 1 and 2 weren't sold to the public as it was an in-house render for the movie and they used version 3 for the rendering of the movie and after the movie was released then then released maya version 3 to the public to use.

So if you remember final fantasy the movie it was all done by maya, and the movie paid for it's development, so it's probably had the hardest alpha and beta testing of any program.