I would presume that one is for trash that cannot be recycled and the other is for recyclable materials. I would not expect either of them to be use for composting. Composting needs something with a lid....

Ours are similar. The cans sit fine down in the frame and are not hard to remove when needed, although I never really remove the cans except for very rarely to actually clean the cans themselves...we just remove the bag from the can with the can in place. They work perfectly and we have not had any issues with it at all.

Both of our cans are used for recycling as we compost and have very little regular garbage. I would definitely not use an in-cabinet garbage can like this for compost as it would start to stink long before you ever fill up one of the cans. I use a large bowl on the counter during a meal for compost and it gets taken out and dumped during kitchen clean up.

I have those in my trash pullout. Not utilized yet since kitchen will be about 1 week till full use. But, my recyclables are just inside the garage door, so my plan is to utilize 1 tall trash can for trash and the one behind it to store an extra box of trash bags and a multipack of paper towels in.

I'm sure things may change as I see how that works out or if my family are messy at disposing of trash and get it all over the items in the back can.

I have this pull-out system. I use the front one for kitchen garbage and the rear for plastic, glass and metal recyclables. No problems at all lifting up the cans and they sit solidly and evenly on the slats beneath. I've never had to clean down there beyond a quick wipe and since the drawer is full-extension, it's very easy to get at any corners and crannies.

The finish on the wood is moisture and stain resistant, most likely a catalyzed finish. It cleans relatively easy with soap and a damp sponge or rag. The finish should not stain from basic food or waste, however artificial dark colorants can stain almost any wood finish if allowed to sit around long enough.

The trash cans themselves can be easily removed from the holder due to their tapered shape. So removal should not be an issue. If you ever need to replace the cans due to staining or breakage, you can find online retailers that sell replacements. You can usually find the can info on the can bottom (capacity, size etc.).

Another suggestion I would make is to explore some of the pull-out trash offerings from Rev-A-Shelf. They offer some trash unit with aluminum frames that will not stain and are easier to clean that wood. No rot or rust concerns either.

We have the pullouts shown by the OP. They're easy to use and no nooks & crannies or screws to clean around. I would not want to have to clean out those metal frames with all the openings, corners, and things to clean around. I'd much rather just have a flat surface to clean.

The bins do fit pretty tightly, so there's rarely much in the "drawer" section, but I do check periodically, just in case.

Mine are used for trash and recycling - we don't compost, so much of what you put in a compost is put in the trash (or down the GD, but we try not to put too much down the GD as we are on septic.)