I took modafinil in the form of Provigil. Wasn't very similar to caffeine. It's more akin to Adderall. However, I still rank caffeine as more productive for me than either Provigil or Adderall. Provigil was weird, seemed to increase my hearing, and put me on edge. I was certainly more alert, but to an extent that was just excessive. I'd pay attention to so many trivial details that it was mentally and physically exhausting me. Things I never noticed before, song lyrics, instruments in songs, people's mannerisms, etc.

Adderall wasn't as bad, but it just wrecked my physical state. Twitchy, nervous, jaw hurt, wouldn't eat. In low enough doses, adderall is probably as useful as a cup of coffee. Long term health risks though seem pretty bleak.

Wellbutrin is another wonder drug that's not always talked about. Increased my concentration, increased my sex drive, increased my athletic performance... But! The first week on a full dose and I wanted jump through a window. Does very weird things to your brain (epileptic seizures included). I described it as being able to feel things in my head that I shouldn't be able to. Started hearing lots of high pitched humming. Apparently all side effects, bleg.

I'll stick to coffee.

I have always had issues that are consistent with low-to-moderate ADD (never bothered getting diagnosed) and caffeine provides a noticeable, but not drastic, improvement for me. I've never tried any other drugs.

It is probably safe to say the effectiveness of caffeine/modafinil/adderall depends on your unique personality, brain chemistry, etc.

Well. I have tried modafanil from two different sources (both were modalert iirc) and noticed absolutely nothing. I tried various doses. I tried taking it before staying up all night and after. Each time was a complete disappointment. So it could be hype, me being unlucky with fake pills or differences in physiology.

I've used modafinil in concert with tDCS (http://en.wikipedia.org/wiki/Transcranial_direct-current_sti...) and have found it very beneficial except for some slight side effects (as someone else had mentioned in the thread, jaw clenching).

Did you build your own tDCS device?

Same thing here. I was thrilled to learn it could be prescribed for sleep apnea and was provided with free samples. I felt nothing. An acquaintance mentioned it did wonders for resetting the internal clock when traveling to different time zones, I'll try it again when that occurs.

There's a theory that there's a group of people that has a genetic mutation that makes modafinil not work for them. That might be the case for you?