It is important to note that this is not an aftermarket ergonomic controller, just a well made controller that has the same dimensions as the originals. Let's just say it's a quality replacement. All buttons are clean and work properly with no signs of malfunction. There was no sync, I just turned it on and started playing. You can either charge the controllers by plugging them into the Switch and charge them together, or you can charge each piece individually with a USB-C cable. The buttons have a better feel than the originals and are easier to find by touch. The D-Pad is nice too, instead of four separate buttons it's set up just like the NES. I use an attachable part for the switch with ergonomic grips, it acts as both a grip and a protective case, which is why I'm so happy with these controllers that I can keep using the protective case I'm used to. If you're looking for something more ergonomic and non-original, look further; but if you're looking for a solid, reliable replacement with serious battery life, then look no further.