[JonathonW]

You used to be able to pin it to a corner-- it was removed in 10.10 (IIRC along with a rewrite of the Dock itself) and never came back. Which is unfortunate, because a top-aligned Dock (on one of the sides of the screen) is way more predictable than the center-aligned Dock; pinned items never moved (unless it overflows and items start shrinking) when the Dock was top-aligned.

[masswerk]

Well, UX, as in "appearance first". (My own pet grief is about the loss the of custom icons in the Finder's side bar. I relied much on those for quick navigation. Now, I have to read… I've still an old Power Mac with an old OS around, and I'm much faster on this one than one any newer machine.)