This is clearly a man who is an expert in his field and whose advice should be followed verbatim!MOI is off the charts when it's full, it couldn't be more forgiving! As you drink it, the MOI goes down as the overall weight goes down (you guys should know this, it's the same physics that applies to golf clubs, all else being equal heavier=higher MOI) so it gets less and less forgiving as you empty it. Once it's empty the only way to make it more forgiving is to have it refilled to increase the MOI again. That's your first lesson for the Grandaddy and one to remember next week.