I've never tried it myself. A girl I know with used to use it quite a bit and, despite still smoking a lot of pot to this day, she will absolutely never use ecstacy again.
Her reasoning is that when you use it, it's the best feeling and mood you've ever had. However, the more you use it, the bigger your tolerance gets, and it becomes quite depressing to realize that you will probably never be as happy sober as you were when you first started using X.
I've heard that it is the ultimate high. Better than anything. I've never taken it, either, but then again - I've never really done anything that would be classified as "drugs", thus my ignorance. :-)