I’ve taken Modafinil extensively while I was launching my first start-up and still working full time. For six months I was waking up at 4am every day, working until 7am, having a one-hour nap, then off to work until 6pm… Bed-time around 10-11pm. I wouldn’t have been able to launch without Modafinil (I’m actually using Alertec rather than Provigil, it’s a bit cheaper). Those days I took up to 1.5 pills a day (150mg) - 1 pill 1 hour before waking up, to make the most of that 3-hour slot, then half a pill half-way through the day to allow me to keep productive at work.
I still use it occasionally, to boost a specific day’s productivity. I think taking it as described (and as I did while launching my first start-up) is abusing it and asking for trouble later, but using it to get an odd boost of concentration (which suddenly allows me to work like a beast for about 12 hours and get huge amounts of technical work done in that time, particularly in combination with a little caffeine) is ok and doesn’t have any side-effects - just make sure you drink plenty of water (sometimes on Modafinil thirst can also seem like a bit of a distraction, but you will get a mild headache if you don’t drink anything). Also, I only take half-pills now, so the max I ever do is 50mg in one day.
It was more about the quality of those hours than about the quantity. Both my day job and my start-up were very challenging (I worked in a large consulting company, at an investment banking client... not the place to fall asleep on the job). The modafinil meant that each and everyone of those hours was highly productive, instead of spending most of that time in a zombie-like state.
Of course I tried coffee. It really doesn't help me that much, though. I end up feeling very awake, sure, but very jittery (not good when projecting an air of confidence to your clients at the bank) and even more distractable (considering how distractable I am to begin with, that's something!). Modafinil, on the other hand, focuses me like a laser.
I still use it occasionally, to boost a specific day’s productivity. I think taking it as described (and as I did while launching my first start-up) is abusing it and asking for trouble later, but using it to get an odd boost of concentration (which suddenly allows me to work like a beast for about 12 hours and get huge amounts of technical work done in that time, particularly in combination with a little caffeine) is ok and doesn’t have any side-effects - just make sure you drink plenty of water (sometimes on Modafinil thirst can also seem like a bit of a distraction, but you will get a mild headache if you don’t drink anything). Also, I only take half-pills now, so the max I ever do is 50mg in one day.
I’m in London, though, not Silicon Valley.