I have 2.4g evry day, and it does indeed kick total ass!!
It is one of the best supps I have ever used.
Every compound lift has gone up 10lbs(in 1 week of use) and some have increased as much as 16lbs. On calf raises I gained 30lbs
IMO there is no need for 6-8g a day. 3g a day will be cost effective and give awesome gains.