I just downloaded and looked at your project file and you might have struggled but you made it work.
Of all the tutorials in the manual this one is likely the exercise that should be updated/replaced.
It was added because people had a genuine interest in modeling realistic characters and there wasn't a lot of official word on the subject at that time.
I don't know if you've seen the links to the rest of the Cooper tutorials but there are tutorials for the entire body.
It's been awhile since I looked at the exercise but I recall there were several pitfalls that should be avoided.
The primary concern might be that the model as demonstrated is overly complicated and at times overly dense for spline/patch optimization.
This isn't to say that adding splines for additional detail shouldn't be done but in general it's best to leave extra splines and patches out.
In polygonal modeling those extra faces might be necessary but with splines and patches extra geometry can equate to less smooth surfaces.
Not your fault!
There are several approaches to modeling faces and it might be good to inventory those so folks can examine for themselves and determine what works best.
The only thing I really see in your end product that might be problematic is 6 patches on either side of the nose (in between the eyes) that have their normal flipped backward.
Otherwise, things look pretty good.
The thing that occurs to me at this point is to review methods that might be used to average out spline bias and placement to achieve maximum smoothness. Much of that has been updated since the exercise was written.
Hopefully Robert will see this and drop a few notes on how this exercise can be improved but... that's not about you.
File this exercise away and know that things get better and splines will flow more smoothly.
A suggestion would be to do a quick mini exercise where you try to repeat what you learned from this exercise to model a (simple/simpler) face BUT... don't use a rotoscope.
The rotoscope is there for detail and accuracy... that'll slow you down... for this exercise you are just trying to get your brain and hand to get a feel for laying down splines quickly and efficiently.
Keep up the great work!
Added: The age old question of whether Quantity or Quality is more important is largely irrelevant. We need both.
But it's important to consider that Quality is largely a matter of time and attention/focus.
If too much time is spent on Quality there is no time left for Quantity... and this will hurt a lot in animation where quantity is important.
As I like to tell aspiring writers... you may spend all your time working on the great american novel and when you finally sell it and achieve success the first question asked will be.... "What else you got?"