Well, there have been a lot of opinions expressed so far about the PMTS vs PSIA approach to teaching. No one has posted yet who has been to a PMTS camp. I have.
The elephant in the room is Harald Harb's toxic negativity towards PSIA and any other teaching system other than his own. Let's call it negative advertising. He trashes everything not his, demands total loyalty, and sticks to a very rigid progression for his students. His certified instructors do the same. PSIA instructors who have experienced his intense denigration of how they teach are as negative about his system as he is about theirs.
None of that impacts the value of the PMTS approach to skiing. PMTS is excellent as far as its technique goes. It is taught clearly and consistently by all its instructors. This is good, and I affirm it. I've learned much of my skiing from the three instructional books written by Harald Harb, the forum discussions which focus on technique, and the free videos he's put online. The consistency in PMTS teaching is very helpful, since you always hear the same thing in the same words.
PSIA, on the other hand, does not promote a particular way to make your first turns, nor your intermediate turns, nor advanced turns. PSIA does not promote a particular progression in its teaching strategy for beginner through intermediate and on to advanced skiing. For this reason, PSIA does not guarantee a consistent teaching approach. Instead, PSIA allows its instructors to creatively choose how to approach a particular client's needs. This means you need to find an instructor who you can work with, who reads you well and who you understand. The issue is the ski industry is understaffed. There are many ski instructors who could use a bit more training before being turned loose to teach intermediate skiers.
When I went to the week-long PMTS camp at A-Basin, I had high expectations. I was very enthusiastic. I expected to learn plenty during a full week, and I was well-prepared. I had been working from the books for years, and had absorbed a good measure of the technique into my personal skiing. But I did not learn anything, except how far I was from perfect. But I found the rigidity constricting. You'd think I would have gotten better at what the system teaches, with a whole week of on-snow instruction, but I didn't. I think if I'd been in another teacher's group (I was in Harald's group!), I might have gotten more from the camp. I also think if I'd known less about PMTS and had spent less time over the years working on embedding its technique in my skiing, I might have gotten more from the camp.
I do find the negativity of PMTS toxic. I don't like the way Harald talks about all instructors who are not certified by him. I will not go back to another PMTS camp for this reason.
I also find PSIA's looseness with respect to what we should be teaching and its resulting inconsistency from instructor to instructor a bit problematic. I'm not sure, however, that rigidity in the teaching progression is the answer. I like my own freedom to teach as I think best. The autonomy that PSIA gives me is good.
If you can find an instructor to work with in private lessons that you really like and trust, that will be a very good option. You can also book PMTS instructors for private lessons. I'd suggest working with Diana if you are interested in pursuing private PMTS lessons.