I really don't think the bees appreciate our concern by providing ventilation for them. They seem to prefer to control that themselves.
I actually ran a little test before I switched to solid bottoms. I had two hives side by side. One with a solid bottom, one with a screen bottom. The solid outperformed the other in every way. More brood, more growth, more honey and no more health issues.
This was in no way a scientific experiment, just a opportunity to see how it shook out. I just don't see advantage to them, even in my climate.