We have a Henchman tumbler
Ours is the original single tumbler and it's great - it takes masses and masses of stuff including grass cuttings and makes amazing compost. In the warmer weather it takes about a month to produce compost.
If you leave buckets under the vents it also produces very strong liquid plant food.
In the winter we tend to fill it in November and leave it until spring when it gives us lovely compost which can be turned into potting compost.
DH rotates it daily in the summer, in the winter it is probably rotated once a week.
Ours was originally sited on earth but it is now on a flat surface (patio slabs) and it much easier to turn - when it was on a slightly uneven surface it always felts asif it might topple while you were rotating.