I was certified OW in beginning of May 2013 and I finished my AOW this past weekend. I had about 20 dives when I started my AOW.
I did enjoy the wreck dive we did as part of my AOW and nearly froze on the drift dive we did after the wreck dive. (I know, 85 deg. water would feel bath water warm to most; however, I do not move much to begin with plus have a tendency to get chilled rather easily. Still waiting for a 3mm in my size to come in to my LDS. Not sure how I use to snorkel in the Puget Sound/Neah Bay area with a two piece 7mil wetsuit...oh, that's right...warm water down the back prior to going in and only being in the water for 30 min to an hour max.) Though it was quite an experience with first filling up a safety sausage and sending it up then getting my gloved finger stuck in the spool. Well, you can imagine what happened next. Fortunately, the instructor had been right beside me so he grabbed my legs and tried to slow down my ascent while I freed my finger and loosely grabbed the string so it could still spool out.)
The PPB was interesting, not sure if I really needed it though. It was the first time I had done a proper weight check both with gear and without. During OW, the instructor eyeballed us and gave an estimate then once we were in the water, he would either subtract or add as he watched us swim about. I ended up with zero lbs which seem to amuse the instructor due to my being the only one with a wetsuit on. With my current tank/gear set up, I sank straight to the bottom (that's with a 1mm long sleeve shorty, 5mm booties, and gloves on). So the only advice I was given was to continue to add or subtract air from my BC as needed though the instructor did say my trim looked better with an extra two lbs added to the front of my BCD to even out the weight of the tank.
The deep dive was fun though. Right at about 50' we entered a silt layer so had about 2-5' of viz till we got down to about 100' then had maybe 5-8 ft of viz.
I had some good learning experiences and I am sure I could have gotten the same just by going diving but it was nice to have an instructor and go through the classes there all the same.