Ephedra/ephedrine works, especially when combined with caffeine. Anybody who tells you differently is wrong. There have been several studies that show it works, and works well over time (over a year straight). It has been tested against meridia and another drug, both of which it beat not only in terms of fatloss while on, but in ability to keep fat off after cessation.
Also, the 'stimulant' effect tends to leave after using for regular periods, however the fat burning ability is not minimized. In other words, it still works even after you can't 'feel it' anymore. Again, this is documented.
I've yet to see or hear, even anecdotally of the fat coming back moreso after cessation of ephedrine. However, if you eat too much and exercise too little, reality will settle in pretty quickly.
The biggest problem with ephedrine is it's affect on the prostate. The older you get, the more likely you will encounter this.