Realize it's been a while but...
I just finished reading all 30+ pages of this thread and have been researching vibratory tumblers. I thought I'd share this one at cabellas : Cabela's: RCBS Vibratory Case Cleaner
They have a $10 mail in rebate through the end of the year, which will help a bit.
I'm also interested in some of the media choices that have been discussed as I also restore vintage watches. In jewelry making they use stainless shot to burnish metal jewelry pieces. Those machines are a little more pricey since the motor has to be larger to handle the weight of the shot. There's also magnetic tumblers (google it for anyone interested)... but I won't even go there. So what I'm looking for is some kind of media that won't round off the straight lines/profile of a watch and that also won't get little bits of dust and particle trapped in the crevices. At this point I'm only thinking about using it to shine up the watch case, not the mechanism, btw. We don't have a lot of extra space, so I'd be interested in finding one media that could do everything, particularly with the addition of a polishing grit like Chromium oxide to the hopper. If anyone has tried any other media choices, please report back with your results.