I successfully completed my AOW last weekend. I think the one class that helped me the most was Peak Performance Bouyancy. The fact that my instructor did that one first and kept returning to it during each subsequent dive really cemented the breathing techniques. I downloaded my dive profiles and was pleasantly surprised that I am now working on a 'fine toothed saw tooth' profile of about 3' - 5' differences in depth. Compared to where I was just a few dives ago (8' - 10'). By better controlling my bouyancy, my SAC rate is just below .5 cu ft/min, too. According to my computer, my dive times are now limited to No Decompression Limits instead of available air!