My son(s) hitting coach is a 60yo former MLB'er who is very down to earth, direct, and loves working with kids. He can be a tough dude when he needs to be, but he truly has empathy for kids having trouble hitting the ball. He has no fancy drills, but he is very good at breaking down what is off just by watching my sons hit off the tee, or in the cage. Sons says he throws the best BP, EVER.
Coach usually can identify what is wrong in the 1st session, but it sometimes takes 3 or 4 1/2 hr. lessons to get the fix to "take". I do know players who take weekly sessions with him, all year long. I can't see how it could do anything but good, except to the bank account. I'm too cheap to go weekly.
It's taken me years to realize what a great resource he is. There are other good teachers out there, for sure, but I appreciate how clear, jargon free, and uncomplicated his teaching is. The guy is a master.