I don't have any of the truerc 4S packs, but I do have a couple of 5S packs. They are the 8Ah and although they are rated at 10C, I've never had any issues with them at all. For a change, I believe that the truerc packs are under rated. At around $150 a pop, they hurt a bit less than the maxamps packs. Just be sure to check the balance taps. I think that you have to add them to your order to get them; I don't remember.