Haven't considered a booster, but I don't think it would be necessary. If I needed that kind of power, I would consider getting a spotting scope.
By the way, did your "demo" pair come with a green wool case? I was wondering if they made changes to their case since I have the green wool one and, to be frank, I think its quite useless. Very tight fit and not room for accessories (this is where I think Vortex had a significant advantage).