I was planning a trip to Cozumel in June that year, and I decided I wanted to dive on that trip. I happened to have another trip planned for march of that year, a short trip to Puerto Vallarta, and I figured that would be a good place to get certified. It wasn't. It was not until years later that I realized how many short cuts were taken in that certification. I felt I was an OK diver, but I was not truly confident. I therefore signed up for an AOW class to take place my first days in Cozumel--dives 5-9. It was a wise decision. I learned a lot from that instructor, and I dived the rest of the week with confidence. I enjoyed myself so thoroughly that my original intent of diving a couple of times every other year during a tropical vacation went completely out the window.
If you dive actively for 20 years as an OW diver and then take AOW so that you will be allowed to do certain dives, you will certainly not see it as a worthwhile course. If you do it when you still need that basic instruction, it will be very valuable.
Here's another thought. I moved to Colorado and learned to ski as a young adult. I was gong to graduate school and had little money to spare. I could not afford lessons, so I learned by imitating others--my Mentors. Years later I was a fairly accomplished skier, and I took some lessons. I also joined a citizen racing team, and took some racing lessons. I was obviously a much better skier than I was when I started, but I was never able to be the skier I could have been, and I was never able to get beyond the mediocre level of racing because of all the deeply ingrained bad habits I had picked up from my early Mentors. Try as I might to implement skills as I was taught by my new instructors, in a pinch I would always revert to my bad habits. My advice now in all pursuits is to get good training early on so that you ingrain good habits.
To give you an example in scuba, I was working with a student in the pool a few weeks ago while an OW instructor was sharing the space. That OW instructor commented about how good my cave diving student looked. He was shocked to learn that this was not a cave diving student. The student had only been OW certified a few weeks before. he did not even have his AOW completed yet. He just wanted to get his skills taught properly so that he could be the best diver he could be as he progressed.