The latest of those citations is December 2011.
They may not reflect the current state of the Android OS.
Android 4.1 and 4.2, codenamed "Jelly Bean", have been released since that time, with a "Project Butter" specifically aiming at GUI smoothness.
I haven't had a chance to use anything newer than 4.0, myself, so I'm merely pointing this out. It could be the same for all I know.