I tried 4800mg Piracetam ED for about a month and a half last year during school... did not have any major effects, and honestly would be hard to distinguish from a placebo, however I think it heightened my thinking a tad, and also allowed me to stay concentrated on the same thing a bit longer. If you have the money, give it a try... especially if you are in school.
Only negative is you need to take quite a lot... 4800 to 6400mg per day. Also, I have heard much about stacking it with other nootropics, such as Hydergine, however some of them are not available for import to the US.