This thread is the first time I've realized that when people speak of a Thumler's, they're normally referring to a rotary tumbler. I had been only vaguely aware that Thumler's made such a thing, and always have wondered at threads where folks complained about their tumblers. I bought a Thumler's UV18 vibratory tumbler when I first started, a long time ago. I can't begin to count how many hours the thing has run, and it's always been perfect. I don't recall breaking the bank back then - I was a teenager, working a teenager's job - but see that they currently retail for nearly $500.
Which, I guess, is a long way of saying that if you're tired of replacing tumblers, I know of a good option.