In reading these forums, I find the advice given is different by region. A trumpet "guru" in one location can be totally unknown to others somewhere else.

There are many "methods" out there for achieving a good upper register. However, I have found that most musicians don't know a thing about writing and therefor cannot get their point across accurately when they put a book out. A good example of this was my teacher, Cat Anderson, the epitome of an upper register artist. The book he put out is relatively useless to those who didn't study with him. Even the exercises in the book are different than those I have that he Xeroxed for me. He was a great teacher, but his book fails to tell of the how and why a student would ask. I use it with my students because I know those how's and why's. I also have them use the Louis Maggio system book (or Claude Gordon's books... same stuff because Claude was a student of Louis ... as was Maynard, Doc, and every other West coast studio player) for upper register and endurance. Everything else you mention, Clark's, Collins, etc., should be continued to maintain flexibility and finger speed. Try Allen Vizzutti's books, as well. They are fairly well put together.

However, the only real advice anyone should be giving here is this: If you want to play in the upper register correctly, you must get instruction from someone who plays professionally as that kind of specialist. Your local college teacher may or may not have the knowledge that a studio player can give you. Most studio players will take on students if you just ask. They will be sitting in front of you and will definitely let you know if you are "sacrificing tone" and how to rectify it. Your idea of what you sound like is usually a long way from what the person listening to you hears. Unless you have a recording studio handy so you can hear playback of yourself, your teacher is the only person who can tell you if you're on the right track to getting the sound you want. In time, you will be reading out of flute books with a fat sound!