I would have to agree with the majority opinion that 68 points is high even for me - who likes high stats. At that point, they are so much more powerful than was intended by the designers that a party of said characters is probably on the order of 2 or 3 levels higher according to their EL. In other words, you would have to increase the EL of their foes by ~3 to give them the same challenge a standard party would have (and not give them higher XP).
I really like Ravener's method of 3d6 base + 9d6 distributed according to taste before rolling. I completely agree that that would increase the variablitily of PBS but at the same time still allow players to have general trends in their characters. Moreover, it balances very well towards PCs with classes that are more stat dependent or have the need for multiple good stats.
I have always used 4d6 assigned after rolling, reroll all 1's. The averages work out to be more around 14 or so (from experience, not from calculations). Moreover, I still find that low stats are possible - they are just not as low as would be detrimental to the character (typically nothing below a 6) . I have developed this system not because of my players, but rather me as a DM. I tend to vigorously challenge my PCs beyond what most would be considered balanced simply because I am such a hard-ass. If they are going to survive, they really do need to be a cut above the rest. (Of course, I grant them proportional experience and treasure, so in my games, those who do survive tend to advance much more quickly and proportionally increase in power.)
I must say though Ravener, your system has very much intrigued me and I think the next game I DM (which will be City of the Spider Queen - starting with drow characters from Menzobarrenzon, rather than your traditional heroes), I may adopt it.