One of the requirements of being a PADI instructor is keeping up to date with the manual/standards. I guess like anything some people do this, some people don't. The people that do are probably the same people that teach good classes, follow other standards and make good instructors. Hence good vs bad instructors from all agencies. I'm one of those people who, upon teaching a particular course for the 1st time that year, reads through the manual sections relevant to the particular course before I teach it. I also, while not professing to teach as thoroughly as some of you guys, like to ensure my students have descent buoyancy, trim and buddy procedures. They may not be perfect at the end of their course but they are definately aware of the areas they need to work on. I will even do extra dives for people if they are not up to standard.
I don't know when these things changed as I only have the 2006 Manual on my PC at present.