Yeah, every console makes usually ships new controllers which differs slightly or more over time. The PS1 controllers had even more though like adding the Dual Analog (was the first one of them official?) and then the Dual Shock. Sixaxis to Dual Shock 3 is another example where they added functionality.
The Wii remote had, of course, the Motion Plus add on before they were incorporated into the main controllers as well. I'll add that the newest batches of Wii Remote Plus controllers also has some modifications; the Sync button which you previously had to open the battery cover to access, is now visible due to a hole in the controller, plus in the jacket. So modifications can either be new features, or just small edits to previous features. I don't know what an upgrade from the DS4 would be though, I don't own a PS4 yet either.
Yep.
