Ok thanks for the Fact. Nice to hear a rational statement on bowling balls for a change.
Let me add something to what Charlest said and also help answer a question about why one ball with a cover hooks more than another ball with the same cover. The thing about coverstocks, is that they start with a base and then there are additives added to the cover. I am going to use 2 Columbia balls as an example; the Mass Eruption and the Freeze Hybrid. If you look at their covers, they are "identical". But what you dont know is that the Mass Eruption has more of an additive in the cover so that it will handle a higher volume of oil than the Freeze Hybrid. Granted they have different cores. But, that plays a part in why the Freeze is labeled as a medium to light oil ball and the Mass Eruption is labeled as a medium to heavy and they are at completely different price points.
Another example is the Ebonite Black Ice and the Ebonite V2 solid. One thing that led me to get the Black Ice, is I heard that the cover was "a version of the cover on the V2". They are supposedly the same cover. However, the cover on the Black Ice is weaker than the V2 due to the additives.
If you want to talk about the R2S covers; lets say you take one test tube with the R2S base, and add 2 drops of an additive from a dropper, then you take another test tube with the same R2S base and add 10 drops of another additive, they are both R2S "technically". But they will be quite different in regards to how they react.
So, there are a some examples to throw out there. Just because 2 shelf talkers for 2 different balls advertise the same coverstock; that doesnt mean they are necessarily "exactly" the same.