I have both the Star and the RCBS. I noticed that bullets weren't getting sized concentrically. Bands were a bit wider on one side of the bullet. Particularly, rifle bullets, even when bullet specific top punches were used. The RCBS gave me good service over the past forty years and I still use it for pistol bullets. In fact, I just rebuilt it this Spring, when the flare on the lube rod wore though the lube reservoir nut. Of course RCBS sent me the parts at no charge.
Nose first sizers aren't dependent on specific top punches. All you need are flat punches. This is critical when sizing spire point bullets. Dropping a bullet nose first, into the sizer, automatically self centers.
RCBS/Lyman are in & out sizers............requires two strokes to lube. Only one is need for the Star. Besides being faster, less chance of concentricity error on an ejection stroke. IMO.