I use a harbor freight two barrel rock tumbler with SS pins. I think I paid 40 bucks for it and it works great. Doesn't hold as many cases as the one above tho. The instructions say 3lbs per drum which includes the water,pins and brass. I run mine at more than twice that per drum with no issues. The barrels are made of rubber so it is much more quiet than hard plastic and it is very cost effective.
I got this one too. I wasnt sure I would care for tumbling with pins so i bought this cheap contraption to try it out. It works OK, but it doesn't seem to tumble the cases as much as it just swooshes them around due to the smooth shape of the drums. Only used it a couple of times and the cases came out sparkling anyhow. Not bad but capacity is very low, especially for big cases.