I own the Humminguru Ultrasonic cleaner. It was $500 when I bought it new about a year ago. It runs at 40 MHz (?) Lower than the much more expensive models. I think it does a really fine job. If it doesn’t clean it well enough the first time I run it through again. Record surfaces look shiny and dust free. It began as a startup. Their challenge was to build the best $500 record cleaner that could possibly be made. I don’t know about the $3500 models, this seems to work just fine. I use one drop of dispersant. Says you’re not supposed to use anything, but I think the records do even better if you have a drop or so of something. No alcohol! Ever!
FYI. I’ve been cleaning records for a long time. I bought my first LP in 1964. I’ve tried everything this works the best for me!
Bent