A while back I tried 30 gram morning doses as I read that studies show it cancels out cognitive performance decreases due to sleep deprivation. Interesting stuff.
Funny, there are several recent studies talking about higher dose creatine and its effects on cognitive function and bone density of older users. 30 grams was, I believe, the max the studies used. I also think the brand of creatine is important, the check for purity is rare in the bbing community.