A guide is a guide, though they may greatly vary in clarity and content.
This one was easy to read, dense and on the whole quite interesting, penned by a former actor and communication coach.
If I didn't learn as much as I had hoped, that's probably due to my university degree and 15 years of practice in teaching. Besides, this guide was very clearly office-oriented, although obviously much of it was transferable to a school-class as well.
One thing I had never thought of but indeed now recognized as true, was that in each group you will find one person playing the role of each of Snow-White's seven dwarves;
Doc - the insufferable know-it-all (Hello, Hermione!)
Grumpy - mumbling and pestering about everything the leader suggests
Happy - the clown who makes the others laugh
Sleepy - bored, refusing to participate, half-asleep
Bashful - full of insecurities, very little participation
Sneezy - incapable of sitting still for two seconds, let alone 55 minutes
Dopey - who never really gets the picture...
I suppose the similarities have more to do with the universality of human character than with any particular sagacity on Disney's behalf, tough...