Generally, you'll see the emulator lag a bit, especially at the start. This is because of the loading process of RetroArch. Eventually, you should see the emulators come into their own. By this time, RetroArch will find the right controllers, add them to the game successfully, and you should be ready to begin your game session. Beyond that, there are some other benefits to using emulators such as Easy Emulator Pro.
On older systems that don't have enough computational power for emulators to run like Acid, emulators will run most games in a similar experience to the original. You'll see a small delay in processing, as the emulator struggles to keep up with the game.
Collectively, all of the emulators of the Xbox 360/One can run the Xbox One game list with varying degrees of success. (Note: It's not possible to emulate all of the titles on the Xbox One list.) The differences between the various emulators are in how they load the game, handle controller configuration, and how they handle the title list.
For the majority of games it will be able to run in the same state as the original XBox. Differences will arise when the emulation has to make game specific decisions like special button configurations or how the game handles powerful/weak controllers (like the XBox 360 controller on XBox One). These options all have to be configured and generally require a bit of work. Some emulators don't allow controller configuration at all.
A handful of popular Xbox games are incompatible with modern emulators. If your favorite game is on that list, you'll have to play it on the original system. Thankfully there are a good range of Xbox One emulators available to allow you to play your favorite games just as they were intended to be played. d2c66b5586