One problem I see with the typical wood nestbox are the crevices where the wood joins: perfect place for mites to hide. I suppose you could caulk the seams to deal with that, but then the wood itself isn't easy to clean or disinfect if the boxes are nailed to the wall in the coop.
I love my storage bin nestboxes. They're made of plastic, so I can take them out, soap 'em and hose 'em down. I dare mites to find someplace to hide in those boxes. I can take the lids off when it's really hot to make them a bit cooler for the hens, or move the boxes into a shadier or cooler spot. And when I had three broodies, it was wonderful to be able to move the whole nestbox with setting hen and eggs inside, exactly where I wanted the hen to be, without disturbing her or scaring her off her eggs.