I do full clears of the entire face via electrology. I use E3000 in Dallas, and they use lidocaine injections so it's not all that painful, except for the painkiller injections themselves. A session right now is in the 4-6 hour range, though I expect the next session to be closer to 6 than anything else, since I had to take a break for a few months after FFS.
Just 15 minutes of electrolysis doesn't sound like much at all. The average male face has thousands upon thousands of male beard follicles on it. A good electrologist can remove a single hair every 5-8 seconds, it seems, so 8-12 hairs per minute. That 15 minutes means just 180 hairs.
Also, anecdotally, my own reading on this topic, which is fairly extensive, seems to indicate that the average MtF face takes 100-200 total hours of electrolysis to clear. A few are fortunate enough to go through less, a very few are unfortunate enough to need more than 200 hours, but the great majority seem to be in that 100-200 hour range with most seeming to be in the 100-150 range. I don't have statistics to back that up, but it's the impression I've gotten from talking to lots of women who have completed their facial hair removal processes.
Laser is different and can clear the face in much less time because it can cover more, if it works. For those for whom laser works, it's a godsend indeed, but for lots of us, it just isn't an option.