The case against compost tumblers
I am complete against tumblers. They don't drain well enough, the compost becomes too wet and starts to smell bad. With a tumbler you are never finished with the pile either. Sludge that drains off the compost is called leachates. This can be toxic to plants. A bin placed on the ground drains away all the leachates. A tumbler holds on to the leachates. They try to tell that it is not leachates and it is compost tea. Compost tea is completely different from leachates. You make compost in a big jar just like making regular tea. The so called trays for collecting the so called compost tea are really trays for toxic leachates which should allow to drain away and you should not put on leachates your plants.
I like to turn my own compost. It builds up my strength, I remove the bin by lifting it up and off. I mix up the compost and I put it back in the bin. You can really hurt your back turning a tumbler that is heavy with water. I saw one in a friend's garden with soaking wet and filled with fungus gnats. It was gross, smelly, soggy and anaerobic. The weight made it impossible to turn. I am a small weak woman, and I could not turn it at all.
If one is still bound and determined to get a tumbler I suggest using Craig's list and find a cheap used tumbler that someone is getting rid of before spending big bucks on a new tumbler. That way when you decide you don't like it you won't have wasted much money on it.