UPDATE: We have been using this tumbler for a year now, and it did a fine job making compost. Most impressive is that it's truly bear-proof... the bears are only able to spin it around but they didn't break through.
It was relatively easy to put together, but I did need help getting the last couple of screws/nuts tightened down. It was designed very well, with features that allowed ease of assembly. Once put together, it was light enough to move into location, and the grips on both sides of the tumbler make it very easy to rotate, without a handle (meaning one less thing that could break). The black plastic creates a high temperature interior that will benefit the break-down process of the composting material. I also like that there are two chambers, so that the compost can be in constant use; one side is creating more new compost while the other side has compost that is ready to use.