I've used all 6v for quite a while. And now I'm all NiMH as well. You can choose (this is how I see it) 1. Same weight and almost 2x the flight time, or 2. 1/2 the weight, same flight time. Since I like to fly for long periods, like all day frequently, I go for greater capacity. I just picked up some 1800 mAh 6v NiMH that weigh 5 oz. Me Likey!!!