What do people feel of the relative merits of tumblers vs fully enclosed bins (like an Aerobin) as far as time and capacity?

How important are critters in bins and tumblers? Seems like they would have trouble getting in there...

How importants are the C and N ratios?

Thanks.

Suggest you read a number or articles and threads on composting. Selecting a composting systems comes AFTER acquiring knowledge on a subject, and considering your needs, resources, yard and local regulations, etc. etc.

Everything else needs to be decided by who has to maintain it.

Consider:
- Access to water
- How are people supposed to add to it
- How much space is available
- How much will be gathered
- How much time do you have to wait
- Is this going to be a digestion operation or one to make as much compost as possible? What's the objective?
- Just how much work is willing and available to go into the enterprise?

The above should pretty much dictate which path you'll take.
..

There is an ideal ratio that will get your compost to heat up fast and finish fast, and you can chase that as much or as little as you like. You don't have to be spot-on to still get compost.

You need to pay enough attention to the ratio that it doesn't get slimy and stinky (too much N, or too much water) or just sit there and do nothing (too much C, or too little water). If you keep yourself out of those extremes, you will get compost eventually. Beyond that, chase the golden ratio as much as you have time, energy, and interest to do so.