I have what is still my only hive on a SBB. I've noticed a bunch of bees often cluster under the hive, on the screen. My assumption, although I can't be sure, is that this happens when the bees are out orienting and somehow go for the screen instead of the real hive entrance and get stuck there, trying to get past the screen instead of looking for another entrance as they can see/smell the rest of the hive through the screen. I've even seen a dead bee half-way through the screen. She must have gotten half her body through and then died there, stuck.
Does anyone have any good resources about the pros/cons of SBBs? I've decided to be treatment free and foundationless if that's an important variable. I've also mostly decided to only use the (portuguese) medium sized 10 frame boxes and need to decide when I need to buy more equipment to do splits and house swarms if I should pick up SBBs or the (cheaper) solid bottoms.