One thing that confused me is that X-Arcade changed its .cfg file when it released X-Arcade 2.0 controls. Both versions of the .cfg are out there, so you may want to make sure you have the correct version. It will say at the top of the cfg file. I used the wrong one and my joystick didn't work, so it sounds like you may have done the same. But, like others have said, you can reprogram all the buttons in Mame in about 5 minutes.
As for other emus, most let you set inputs for each button. However, they don't let you change GUI controls such as "exit program." This sucks for the X-Arcade because you don't have a dedicated "esc" button and most emus are hacked to quit on esc. I just said the hell with it and just play Mame. I was lukewarm about playing console games on an Arcade cab (for anti-nostalgia's sake) and that was a deal-breaker. But, if you want to set it up, here's how:
Follow the instructions for configuring the buttons. You must program all buttons. You can't just modify one, which would be great. You need a keyboard, too. Set up all buttons except the one you want to use for exit using Mame's mapping (or anything you want). Then set the exit button to "esc." Note that X-Arcade can quit Mame using a button combo (Player 1 button 1 + Left pinball button, I think) because it's written into the .cfg file. But this won't work for other emus.
I got the X-Arcade BYOAC buttons, sticks, board and wiring kit and love the way they play. The board is fine in terms of playability, but the way it needs to be wired isn't great if you want to customize it at all. The wires are too short for many cabs, too. I wonder if the X-Arcade 2.0 included a better board, because many on this site hammered the old one.