Sure, I'm an advanced skier and I like to take a private lesson at least once a year to fine tune my movements and progress in certain areas. Without going into a long spiel I have taken 2 multi-hour lessons several years ago at Timberline & Liberty. Neither instructor was able to communicate clearly the movements he was trying to teach. Furthermore one of the instructors (can't remember which one) was trying to demonstrate 2-footed skiing but he lifted his inside foot at every turn. He also insisted I ski with a really wide stance which really didn't work for me. I think he was preaching the party-line (PSIA) but he couldn't really explain why I should do so.
At Lake Louise in 2001 I took a bump clinic. The instructor was an incredible skier but the entire 2 hr+ class consisted of him skiing and us either watching or following him. I am talking absolutely no feedback.
My wife took a private in Vermont as a Lvl 4-5 skier and that one reportedly consisted of her following the instructor with very little demonstration or feedback.
I have had one good experience by chance in NH and a several great experiences through recommendations out West and with Otto at Liberty.
Lessons are expensive so do your research and ask around.
BTW if anyone is going to Steamboat I can recommend an incredible Lvl 3 cert. instructor.
I am now looking for an instructor for a full-day private at either Alta or Snowbird so if anyone can recommend someone please feel free
(Well-so much for a non-long spiel-sorry