My son, who is about to be seventeen years old, is a terrific skier. He has what appears to be absolutely flawless form. He is graceful, and his movements economic. He skis bumps like they're the bunny slope. I would cut of my left something-or-other to be able to ski half as well.
Where did he learn to do that?
Certainly not from me. Certainly not from in-person instruction, since he hasn't had that since he's been four years old, and all they taught him was the "pizza wedge".
I know where he learned that! He watched videos, and then he imitated the skiers he liked best. He watched non-instructional videos, like Rob and Eric DesLauriers with John and Dan Egan, Glen Plake, whomever. He watched instructional mogul videos with Nelson Carmichael, John Smart, Mike Douglas. He HATED Lito's vids - boooooooaring. Once, we got to ski with John Egan, and my son just imitated him [for the moment, because my son's form is more of a refined sort].
That's my son. He's naturally athletic and has been skiing since he's been four years old. . . and I? Well, as those who attended the EpicSki Academy and the gathering in Utah this year can attest, I'm a very, very average skier - improving, to be sure, but average nevertheless.
So my answer: Videos work very well for some people and not so well for others. In my own view, the slowmo stuff from Lito is close to useless, but the visualization from John Smart and Mike Douglas is priceless, and Nelson Carmichael's lessons with his sister, an average skier, are encouraging.
So, try it - you might like it. Can't hurt, and if you leave Lito out, the others are very entertaining.