I have to say that I used both rx packs and now the Novak Booster. The booster is a shrunk wrapped lumpy pc board that is not exactly small, but I would not pry it out of my car at this point. It's clearly the way to go for multiple reasons. If a rx pack uses 50mah per 8 minute run, the look at it this way:assume that a booster uses double that even though the voltage is not quite doubled, call it 100mah consumed over the course of 8 minutes. That's .1th of an amp or .012mah/minute taken from the main pack. That's a tiny load from your battery.

Bottom line: way easier racing!

Brian