Genuine question, what do you think is missing?
I wish it was slightly easier to type a #. But OTOH it's /way/ easier to type accented characters (in either the fast way for regular use or the slow way that's much more discoverable) or different types of punctuation. Without memorising numerical codes, which is what I remember from Windows.
I certainly don't miss all the extra navigation keys, when I have the meta-keys and cursors right under my fingers, exactly the same on any Mac I use.
I'm struggling to remember more than minor differences from a PC keyboard. N.B. I'm in the UK so that might make a difference.