Probably not my place, but what I understand is that they are domes that have weights outside the foam, in the hot glue dome itself. Weight/aerodynamics are so optimal that it gets unfair to use them.
Yeah, pretty much- and there's a greater risk of the weight ripping out/off of the foam. Funny to see happen when you're dicking around in your backyard (lolwut where'd the weight go?) but never funny for nerf war where you're shooting it at other people...