I took the Ho course and thought it was helpful. My institution paid for my travel, hotel, and course fee though ... I might have been more critical if I'd had to cough up $3K for it all. I don't think I really got $3K of value out of it, but I got something out of it.
It was good to watch other people take the public exams and flounder around. It was reassuring in a way, made me feel better about my chances. It was also useful to see what kind of answers were pounced on, how straying from the "answer the question and STFU" strategy opened them up to attacks from the examiner, how nonverbal things like fidgeting and extra 'ums' made them look bad. And it was a few days of forced out-loud practice with strangers. But most of the other attendees' on-stage screwups were knowledge deficiencies. They would mostly do reasonable things, but get sunk by not knowing how to interpret a blood gas or boning up ACLS.
And then Ho would spend 45 minutes teaching the class how to read a blood gas or talking about amiodarone dosing for pulseless vtach. Really, a LOT of the course was devoted to reviewing facts and correcting knowledge deficits because that's where most attendees were weak.
I also followed the 2-day course with the 2-day "must know cases" session. My gripe about that session was that we were mostly paired off with other students. You get yourself a bad partner and you may as well be at home by yourself talking into the air. I went to the course with a residency classmate and we mostly paired off together ... but hell, we could've done that at home.
I passed first time through, and for that I'm grateful. Mostly, I know I worked hard and feel I deserved to pass. But there's some luck and randomness to the exam. I know too many smart people, good anesthesiologists who failed their first attempt. To an extent the review course salesmen prey on the anxiety this creates. I think it's a rare candidate who'd be a failure, if not for a weekend with Ho turning him into a pass. I bet most people who fail aren't making glaring, ridiculous kill errors. I bet they fail by small margins. If you think a review course might help smooth your edges a bit, maybe it's worth it.