Don't get too carried away with the hype about Provigil. It allows you to sleep less and may cause a mild increase in focus, with possibly fewer long term effects than amphetamine-type drugs (speed, ritalin, etc). IE Provigil users don't seem to turn into tweakers.

It is safer but less effective than good old fashioned amphetamine for actually getting stuff done.

If you're just a regular person trying to live a semblance of a balanced lifestyle (for this purpose I will include working a regular 8-to-6 job) the biggest effect of provigil is likely to be to make you say 'so what?'

If you are used to the caffeine-shakes and twitches that come at the rough end of an all-nighter, Provigil can take that away to some extent. The psychological price you pay for doing this too often is unknown, though.

Having said that, it is useful to get you out of a jam if you stay up partying all night and need to drag yourself to work the next morning.

And best of all, if you are in the UK, the NHS pays for it all. In other countries you often have to pay up to several USD per pill and it can take up to 4 pills to be effective.

Edit: Based on my experience, I would consider use of Provigil during a true work crunch or crisis that can only be solved by a burst of long work hours. However, if your masters get used to your performance at that level under those conditions, you might learn more about the expression 'burning the candle at both ends' than you want to know.