Real CESA's are still required for PADI OW certification, in addition to the one in the pool. NASE only does the pool CESA, but they certify only a handful of students a year.Perhaps it was my instructor then (circa 1985) versus what I've seen in some courses these days. When I got certified, we did two solid weeks of pool work and conducted a real CESA instead of a mock one in a swimming pool. Also (and my memory could be wrong) the PADI OW manual was more substantial. I seem to recall detailed illustrations and explanations of pressure/volume relationships as well as some basic illustrations and descriptions of how regulators work. At least the regulator information is now in the Rescue manual. Also, the new manuals seem to be presented more like "sound bites" of information that rather than detailed descriptions. My 2 psi
The requirements for what must be done in the pool are a bit more than they were in 1985. The amount of time spent in pool work is however long it takes to get the work done. there are shops that do it over several weeks now. The PADI OW manual today is much better than it was when I was certified. The manual is carefully laid out in keeping with modern instructional theory on course design, with frequent check quizzes and other design features to enhance understanding and retention.
I don't know of any information missing from the current OW manual, except that the ones that are designed for the computer version of the course do not include tables. THey do, however, have detailed explanations of how computers are to be used in the dive, and they have an online computer simulator so students can practice and understand more fully how they work to deal with decompression issues.