7º is definately for the beginners that don't have good collective management. It's like setting DR on the cyclic. The less you have, the more precise you can be with your sticks. So while experienced fliers can use 12º+ of collective, that may just be a bit too twitchy for someone that is just getting into the hobby, or grabbing their first ccpm heli.
I do normally state that I suggest 9º of collective, but 7 will work and will soften the stick feel and keep them from over correcting.
I do plan on doing updated videos that are more clear, but without a helicopter, I can't do it lol. Need to get another one and start on them.