After many many flights on my packs (some with 600 in one summer), I found that they are not that great and a Nicad put under similar conditions will outlast them, so I went back to Nicads. The beauty of it is since I really only need to run 4.8V and 1000 mah, I only gained .5 oz over the 6V 1600 mah Duralite that I ran, are they worth it, I dont think so and I certainly wont be going back to them. All my packs eventually failed due to use, 4 - 1600's , 1 - 800, 1 - 1600 TX pack, and a 12V 800 pack on my IFO. I have never lost that many Nicads in such a short period of time.