Hey thanks for this post! ☺
I don’t really understand why you use the float property after all and I may missed something. Yes it works and the problem is fixed but we loose all the power of inline-block. One of the most useful particularity of inline-block is to be able to center things into a container without any fixed width.
I know that when you apply a float property to an element, the display:block; property is automatically assigned behind the scene, that’s why I think the display:inline-block may be useless in your last example.
Anyway, I agree that display:inline-block; for layouts are not reliable but if I need to use it for another feature, here is my favorite technique to get around these spaces: http://codepen.io/anon/pen/OPdvbr