Zero problems, no reason to try anything else. In actual use, with SNES9X and various ROMs over the course of today, I found that the controller performs solidly, if not perfectly. Make sure you are using the correct keys.
In this video I show you how to set a wireless controller on SNES9X using a PC (Windows 10).
Make sure that the code doesn’t have any space. Can I use any controller for legit speed runs such as that or a fightstick? The controller has pedal/buttons on the back that I can map to directional buttons.
It of course only works in apps that were designed to accept a controller, so forget about using it on app store apps. If that's not working, I would wager something is messed with your controller or input driver. RetroArch implements rollback netplay (similar to the netplay code found in GGPO). The mapping utility isn't needed for SNES9x, but I use it to make profiles for lots of different programs and games, so I just have an SNES9x profile. Open the Retroarch menu when a game is running ( F1, by default), select “Quick Menu -> Controls -> Port 1 Controls” and assign the controls there.