For a low buck tumbler it is tough to beat the franklin arsenal model for $41
http://www.amazon.com/Frankford-Arse...8318422&sr=8-1
Mine runs for 60 minutes about twice a week. I try to process what I pick from the range as soon as I get enough to fill the tumbler. I do not deprime before tumbling.
I use half corncob media and half crushed walnuts (both from the pet store) with a few small scraps of old dryer sheet fabric thrown in each time to help keep it clean. A capful of Nufinish goes in and as soon as it is mixed in, in goes the brass. A "spider" ladle or kitty litter scoop does just as well for me as a media separator.
I could tumble longer and get super shiny brass but I am looking for just enough shine that I know it is clean, so I can spot defects when loading, and to make the brass easy to see on the ground.
I tried to go without a tumbler at first, using the wash and dry method. Tumbling is much, much easier plus moisture is never an issue.
edit- this is a pic of a handful of brass that I just took out of the tumbler since I first posted this. 60 minutes.