Hey vertiis,
The modelling you've done looks great! looking forward to seeing the rest of the head . I have to admit that nurbs are no longer my prefered surface-choice when doing organic modelling. I know this sound a bit contradictionary but I just don't find patch-modelling to be as intuitive as box-modelling is. I think sub-d's (as you mention yourself) and even polygon modelling seems a lot more straight forward. I can highly recommend "connect-polyshape" which can be found at www.highend3d.com which we use for all our organic-modelling.
Jeppe
Jeppe Nygaard Christensen
Ghost aps, Denmark
https://www.ghost.dk