How much ice to add to a boston shaker?

I'm seeing a lot of conflicting opinions on how full of ice a shaker should be. Jeffrey Morgenthaler's Bar Book says that the base should be filled to the top with ice. Death & Co often mentions 3-4 kold-draft cubes. Others say fill it half way.I assume there's something to be said about dilution, but then there's all that stuff about how at a certain point adding more ice won't chill it any faster...I mostly use the small tovolo cubes, and it would take quite a few to get my boston shaker all the way to the top.What are your thoughts on this? http://www.reddit.com/r/cocktails/comments/3ewjtw/how_much_ice_to_add_to_a_boston_shaker/