What Steve said and...
If you take Diamox, it is not a panacea and comes with its own set of problems. When I start it back up after not using it for a while my body does not particular care for it, so I have ease into the standard dose. Taking Diamox is not a guarantee of all symptoms AMS being eliminated. I have sleep deprivation and appetite problems regularly while dosing.
Then there is the wall, in SoCal we get to 11,500' and most who do this trip are from this part of the world. Many start walling at between 11,500' and 12,000' there first time up. I believe this has to do with what elevations you are use to hiking and knowing what to expect when reach an elevation range. I rarely have these types of problems in the Sierra, including first trips of the season.
