Well… production cannot be the same on each phone… I love my X and everything works nice & smooth. I just compared my old 7 plus and X, and noticed the X 's power and volume buttons are slightly different. My X buttons works 100% fine, and is good to use, just curious because noticed in my finger that power and volume + "upper" sides are hint lower (its very hard to even see), and buttons are smoother to push. I don't think that this is producing issue because both buttons (power & volume +) on the both sides are similar on the "upper" corners. If you push your power and volume + buttons upper corners - are both buttons smoother to push? Do u see any differences?