I bought the non- autoflo model on sale from Midsouth (for $69?) and love it. I have tumbled 10k .45, 35k 9mm, and ~4k .223 in the last 2 months. I use "10 dry quarts" of the 11 DQ sized lizard bedding Walnut bag from petstore in every load of tumbling. I fit 1k .45, 1300-1400 9mm, or 7-800 .233 in each load with good effect. Rarely use corncob.
Only modifications I did was replace the inner wing nut with a regular nut (catches pieces or dryer sheet or paper towel if not), and minimize the threads poking out of lid for easy on/off of top wing nut. If it sounds loud, add more media. Some have sleeved the exposed threads inside bowl with a straw to good effect.
Hope this helps.
Justin