I think all continuing diver education is valuable, and as a PADI, guy, it is my opinion that properly taught, the AOW class is an excellent course. As to moving on up with your credentials, I have to go with kitty_kat's komments. (typo intended- perhaps a great title for a blog?)
To be a competent divemaster and a competent instructor, you need to have some real diving experience, and in as many varied environments as possible, unless you only intend to ever operate in a single type of environment and teach and lead divers who intend the same. Cold water, warm water, current, calm, surge, surf, shore, boat, salt, fresh, good viz, low viz. The more experiences and the broader range of experiences you have the more you will learn and the more you will learn in the professional certification courses. It's not just a credential, but competence, that makes a good DM and a good instructor. I encourage you to do AOW and Rescue on you schedule. But I also suggest 100 logged dives NOT INCLUDING TRAINING DIVES before you start the DM program, and then add at least another 50 before starting an instructor program. That's just my opinion, but it has been arrived at over 12 years of being a PADI pro and watching scores of new DM's and instructors go through those programs. Those who have been diving a lot are a lot better dive professionals, in my experience.
DivemasterDennis