I don't know that it makes much difference to the bees, but rather the Beeks. Mine has only one entrance, a slot about three inches long by three-quarters of an inch high, along the side bottom, biased to one end. The bottom is screened. Mine has a landing board, but I don't think that a landing board is necessary. What is necessary IMO is a way to reduce the size of the entrance or plug holes so the bees can better defend it when necessary. My reducer cuts the opening down to aboout 1 inch by 1/2 inch, but I could easily fashon any smaller size.
I inspected last weekend and added the last couple of bars that will fit. So mine went from a couple of bars of cut-out to full in about a year.