I have two Frankford Arsenal tumblers and a RangeMax, which is identical to the Frankford just a different colour. I use them constantly, 2-3 times a week, for 5-8 hours at a time. Oldest one is about 4 years old. Worst problem I've had is the threaded ready-rod came out of the RangeMax one, had to empty it and re-screw the rod back in with some lock-tite, no problems since. Just gotta make sure you don't overload them, 50 30-06 cases at a time or so, and don't overfill the media. Make sure its churning good when you switch it on and not standing up all the cases in a spinning line. Different types of media have different characteristics to them and can affect the volume of your tumbler. Crushed walnut is heavier so you get less in the tumbler than untreated corn cob. I'm planning on getting a Lyman wet tumbler next time Cabelas has them on sale. I've seen the results guys have posted from wet tumblers, gotta say I like the "shiny on the inside" look.