Hey, it depends on you, dude! Don't listen to these naysayers! Xanax and X together get you crazy fucked up and feeling great. Yes, your precious roll may not last 7 hours, and you may not remember all of those super-meaningful insights that make x use almost like a religion, but man oh man you won't have to worry about jaw clenching or muscle cramps.
The last four times I've taken X I have also taken a Xanax beforehand. It makes the comeup hit me so much better, personally. But don't go taking those two together and die because the last sentence of my post is this: Ecstasy and Xanax are bad for you and when taken in conjunction can quite possibly hurt you very badly or even kill you.