I think this argument has been going on from the dawn of time, and even wheel manufacturer's all have different takes on it (some even say that lug centric isn't a "real" term, that it's something people came up with and has been adopted in). In reality, right lug nuts for wheels, enough stud poking through and in good shape, your gonna be fine. But if you want that gap in wheel bore taken up, they make rings for that. I've talked to some high up GM tech advisors that say it's main purpose is centering the wheel, not really meant to hold weight. Shoot, most of these "hub centric" cars just have a tiny lip for the rim to sit on to center it. I truely believe that's it's main purpose. As far as the cone for balancing a wheel, I pretty sue they use the cone because it can be used on 95% of the wheels you balance rather than having to switch bolt pattern plates. I don't think it has anything to do with hub centric etc, it has everything to do with ease and adaptability in a work environment. Makes things cheaper when you only need one cone, also saves alot of time.