Erm. Very much a matter of perspective, I'm afraid.Don't buy Call of Cthulhu is the first good step.
Purchase Raiders of R'yleh, which is a 1000% better in every way.
The mechanics of RoR appear to be derived largely from the MRQII/Legend/RQ6/Mythras branch of the d100 family tree. Many people like those, and find them "better in every way."
For other gaming groups, those mechanics are a Hard Nope (for those wanting a quick overview, the Mythras folk at TDM have a stripped-down quickstart, Mythras Imperative (alongside some nifty other freebies).