i have the smaller 5lb Harbor Freight one - i did have one of these fall apart on me the 2nd time I used it but they replaced it, that was prob 15 years ago.
I dont use it that often, but i use the walnut shell stuff from the pet store, in fact i just got some Monday, $7.99 for this bag.
They're great for tossing in tedious, small stuff and frees you up to do other things while your parts are tumbling. I don't throw screws in there anymore because the walnut medium gets packed into the screwdriver slot and you have to clean them out. As an additive I use a "heavy cut" compound similar to Novus 3.