The official attitude is that if you need to "hit the bottle" you should go down... In practice people sometimes use it as a refresher- I hit the O2 once just to see if it would improve my night vision on the summit- It didn't seem to... The main use of the O2 is to revive visitors that pass out...

The link you sent said there were no determining factors in who has a hard time with altitude... That isnt quite true, gender plays some factor- males have larger lung capacity, and females seem to be more vulnerable to altitude effects... most people of either gender seem to be able to handle it for short periods.

I have seen guys pass out up there but women seem to be more susceptible...