I believe that end-grain cutting boards are better for your knife then long-edge cutting boards.
However, I had no good reasoning for that belief. Is there any evidence to back up my belief?
Also, I don’t think glass cutting boards a a good thing for a knife’s edge. And I’m okay with the polyethylene boards, but they are like an ugly hunting dog… great to use them but not something you care to show off. 
Merry Christmas everyone!
Michael