Options to include the items omitted from the GSR package was always available to the RS, but only if you were ordering from the factory. You could, if you so wanted, outfit your RS exactly like a GSR.
When MMC launched the VI, they included another variant to sit between the RS and GSR, which was called the RS2 or alternately, RSX. This particular variant contained most of the creature comforts from the GSR but deleted AYC and ABS from the equipment list. The RS2 did not, however, share the steering rack and the gear ratios from the RS.
If, like cyilaw asked, you are asking about the differences between the ratios of the 6-speed trannies used in the RS and GSR, it's the same since the 6-speed gearbox came standard on the VIII GSR and was as option on the VIII RS. With the IX, the 6-speed gearbox became standard on both the RS and GSR.
Hope this is what you wanted.