Just fired up a HF vibratory tumblerthe 18 lb/$160 ditty. Very nice wave action of the media, says my buddy who's been tumbling shit for 40 years.
He uses the tub type (about 24 x 12 x 12), very heavy, with the very expensive epoxy lining and 1/2 horse motor, noisy like an SOB.
The HF seems actually better for smaller parts, like dremel arbors, mebbe stuff up to 1 cubic inch, and is very quiet, not much noisier than a dehumidifier or air conditioner -- proly depends on the media as well.
The biggest bowl-type vibratory tumbler I've ever seen is rahcheer in Westchester, NY, and is the size of a room. 12+ feet in diameter, could easily tumble 6 ft bars. A dozen+ people could jacuzzi in that thing.
Used for tumbling aluminum, gave aluminum a proprietary zinc-like corrosion resistant finish. Kinda cobby, but kinda cool, as well.
The HF tumbler gets an A/A+ so far, now it's just a matter of its longevity.