Well I have had a cheap tumbler and then I got the Thumlers uv45 tumbler. The Thumler blew a motor in just over a year so I got a new one. That one lasted a month. The design of the thumlers was sketchy to say the least. The motor looks like it should be $20 but is $130. It vibrated apart the first time. The top and the bottom part of the motor is held on by tabs, no bolts. How you mount the motor is to have 2 plates on each side of the motor and really long bolts that go into the base. Tighten the bolts down too much and it will squeeze the motor causing friction. Keep them loose and it will make a racket. The second motor was definitely blown by the bolts not being tensioned properly. It would have been much better if it just had spacers between the top and bottom plate to make sure you couldn't overtighten it. But that would have cost too much I guess. Did I mention the thumlers was $600? The total parts cost on this thing had to be $100 max. Well I had some parts that needed to be polished and I happened to be at harbor freight. They had this tumbler on sale for $170:
18 Lb. Vibratory Bowl w/ Liquid Drain Hose
Also had a 2 year warranty for $50 and a 20% off coupon. Got it for less than $200 total with tax. Set it up and ran it and it was pretty good. I haven't taken it apart to look at it, but it definitely didn't heat up like the thumler did. I ran it for 24 hours straight and it was just slightly warm to the touch. The thumler I think would have been a bit quicker but not enough to justify $400 more in my book.
If you are looking for a tumbler to try out, the price can't be beat on this. Nice part is if it does crap out I can just walk in with it and get another one.
-Keith