For years many of us struggled to describe the nature of the 'Box Model' to people; of how the various elements were calculated in respect of their dimensions; we explained the issue with IE and the - then named - 'Broken box Model' we explained how this box model differed in it's approach to borders, padding and content width, how to deal with two models, hacks & filters galore, if pressed further we might have gone as far as to try and point out that the W3C gave a reasoning of why the box model had to be broken down - in respect of dimensions - into separate parts as the 'content' had to take a dimension and the other aspects had to be added to that width so as to preserve that content dimension.
We watched and wondered as the Specs toyed with proposals over the years for a box-sizing property it was included then discarded as unworkable then brought back until I for one gave up caring whether it ever saw the light of day, after all we had a model that appeared to work.
Now that box-sizing is a reality I wonder why we need it, I wonder why on earth the content-model ever really existed, if as it appears now it is possible to have IE original model, a model that I remember some stating was in fact a perfectly workable one and that after all IE model came before the W3C's version.
Years spent wrestling with two box models and yet it feels now as though in reality it was never IE that caused the issue as we would aggressively point out but in fact the fault of the W3C.
It tends to further my feeling that the W3C doesn't serve us well really.