You don't have to go the GUE route to get good instruction. And sometimes going that way results in less than desirable results when the personality of the instructor and student don't match. I have heard this from students who experienced it.
What you want to look for is an instructor that goes above and beyond the standards for their agency. There are instructors from every agency that do this. Some are easier to find with agencies such as SEI, PDIC, NAUI, RAID, and SDI/TDI whose OW standards are higher to begin with.
SEI,PDIC, and NAUI all teach rescue skills in the Open Water class. RAID mandates neutral buoyancy.
SEI and PDIC teach freediving skills before putting students on SCUBA and you have to master mask clearing and buoyancy using lung volume prior to putting a cylinder on.
I wrote a book on basic open water training and included are chapters on how to interview an instructor and shop, as well as how to decide on further training.
What you have to realize is that the instructor and shop ARE NOT IN CHARGE OF YOUR TRAINING. YOU ARE!
When you choose a shop or instructor you are hiring them to perform a task FOR YOU! They are your employee that is being hired to train you in specific skills and provide academic knowledge that is designed to keep you alive in an environment that is normally hostile to human life.
In my book there are 21 interview questions for the employee you are hiring (instructor) and 20 for the shop with suggested answers you want to hear. You can find it on Amazon by searching for "SCUBA: A Practical Guide for the New Diver."
Some examples of those are
1. “When did you become an instructor?” New instructors are not necessarily bad news. They may be up on the latest trends in teaching and have recent knowledge of new theories and science. An instructor who has been teaching a long time may be set in his or her ways and teaching out of routine, but also brings many years of experience to the table.
2. "Have you had any large gaps in your teaching career? How recently? How many courses have you taught in the past year?" You want someone who has been teaching consistently enough to maintain sharp instructional skills. This requires teaching at least a few courses per year.
3. “What is your certifying agency?” While most agencies are recognized around the world, some are better known, and not just because of size. Agencies vary in the comprehensiveness of their Open Water curricula; some now leave out what many consider to be essential skills and information, while some have a reputation for producing skilled divers who need little or no supervision. Given that a SCUBA certification is a serious issue, it is in your best interest to do some personal research, deciding for yourself which agency offers course content that best meets your needs and expectations.
4. “How much time is required for the course?” A comprehensive course cannot and should not be taught in two weekends, in my opinion. The course should allow you enough time to absorb the information and practice the new skills that you are given.
5. “How large are the classes?” This is important because the more students in a class, the less individual attention. Even if the instructor has certified assistants, he or she is still responsible for your instruction. In addition, a large class often leaves less time for students to just swim around and get comfortable with new skills.
6. “What equipment do you provide and what do I as the student need to supply?” Some courses supply all gear while others require the students to supply things like mask, snorkel, fins and boots. If you must buy some personal gear, look for a shop that allows you to try out those items in the pool before purchase. There is no reason to spend money on gear that you soon find out does not fit or is not quite right for your style of diving.
7. “Is your class schedule set or flexible?” In some cases the schedule is set by the shop. This may work for some people, but I have found that many students require more flexibility due to work, school, kids, or all of the above. Many independent instructors can tailor classes around the student’s schedule at little or no extra cost.
8. “Do you teach skin diving skills?” One of the simplest ways to build comfort in the water is to teach students basic swimming and skin diving skills. In fact, a good instructor will use the swimming and skin diving portion of the class to gauge the comfort level of their students in the water.
9. “What methods do you use to teach proper weighting?” Weight checks should be done at the beginning of every pool session, as described earlier in this book in the Buoyancy Control and Trim section of Chapter Two. Some students may require extra weight in the initial sessions, but by the end of pool training, they should be properly weighted and doing their own weight checks.
10. “What methods do you use to address the panic cycle?” Panic can kill a diver. It is brought on by stress, and stress is created by a diver being uncomfortable with a given situation. This feeling can be minimized by addressing its causes in confined water and in the classroom. The various stress triggers can be identified, as well as ways of dealing with them. This is called breaking or interrupting the panic cycle. Not every course offers this critical piece of education, so check specifically for it when you interview an instructor.
11. “Do you teach students to perform skills in a horizontal position from the beginning of the class?”
There are more and hopefully you care enough to come up with your own.