I've been using it for a few weeks. I have a generic version modalert.

It is not like ******** at all. It essentially gets rid of the "sleepy" feeling and even seems to give me a good mood. It helped me concentrate and is supposed to have cognitive benefits as well. I take it at 5:30 and feel wide awake and great for the work out in the morning.
I want to try the non generic from cephalon to compare but I heard it is really expensive and not usually covered by insurance.
I purchased mine online from www.mymodafinil.net