If you want to use the tank on a reqular ego type battery, the cone/beauty ring will make it look better...although it would still look a little foolish on anything other than a fatter ego battery. I have used a protank style on an ego with this sort of beauty ring...kind of top heavy but whatever. The beauty ring does help to stabilize it somewhat.
There are many tanks around that use the ego threads (evod, T2, T3, PT2 mini, etc). There is not really an advantage other than some stability and cosmetics.