A creatine loading phase followed by a maintenance phase has been shown to work, as has taking mega doses of creatine for myotube regeneration.
It would be fair to stay that alot of the results of the creatine studies have been ignored by the supplement companies simply to get you to take more of their product in order for them to make more profit.
ATP regeneration will quite happily occur in 3-5g doses, and a doses of that level should cause no side effects such as tummy upsets.
Beef also contains approx 4% Creatine - so eat 1kg of beef and get 4g of creatine.
So in short, 3-5g doses should see you right - with little or no sides as would be experienced during a loading phase. I currently take creatine as a supp on training days only - others prefer to stay on it for longer periods of time and then come of for a while.
Creatine and Athletic Performance: An interview with Dr. Paul Greenhaff