Bottom Boards... Screened or Solid?

To screen or not to screen that is the question.  Let's hear some feedback members!  How do you bottom board?  Just like every other beekeeping question, I expect we'll get a variety of answers.  I've heard people say to use the screened board year round, the solid board year round, or a combination of the two.  In the comments section below, I'd love to hear your bottom board practice as well as an explanation for why you favor your practice.

SCREENED

SOLID