Re: Top Entrance -- Pros & Cons?
Most of my hives have both top and bottom entrances a-la Mangum's design. The bees tend to fully propolize the top ones shut in the winter (so I guess mine prefer bottom entrances) and as a result they get condensation in the hive. The fix I use is to slip in a twig under the end of a bar behind the brood nest (away from the entrances) - this keeps the hive free from condensation.
While I have been told many times that bees can't overwinter in a top bar hive - mine do a darn good imitation of it.