The ability to update Xbox controllers, though when mine dies I'm probably switching to a similar priced high end brand with better joysticks.
And on that note, I also miss being able to assume anything I want to use or install is available for my operating system. I was looking a month or two ago at buying one of 8bitdo's pro 2 controllers, but it didn't support Linux. I never had to check if anything was windows compatible, everything either was or loudly said it wasn't.
Still not going back