Nurbs are indeed not the most usual character modelling tool, though i've once seen faces made by this guy who modelled with nurbs patches i maya and damn those were nice models! whatever works for u works for u :P but in general i'd say subd's are indeed easier.

Ngons and Triangles are always a subject of discussion, it depends on software ur using and how well it deals with them, but also it depends on what you'll be using the model for.

Triangles can be great for quickly modelling creases, but if you're going to animate they can turn into a real pain.

5sided ngons can be a great cheat on curved surfaces that just wont stop pinching and 3dsmax is known to handle them very well with it's meshsmooth, still they can form a problem during animating and u'll want to avoid them on surfaces that'll distort a lot during the animation process.

If ur modelling for use in a game engine u'll also need to watch out, some cant handle ngons too well, others start acting strange if u import a quad-model with a triangle stuck between all quads and split the triange into 2 or 3 triangles.

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