I owned both balls.
Ironically, I tried both drilled pin axis. With the Pin-Axis drilling, the Rock Pearl did better. (I guess it's a more "rolly" core.)
However, having thrown both balls with somewhat normal drillings, I think the Ricochet has a cleaner backend -- as a new ball. Once the cover changes, it reads the mid-lane pretty aggressively.
So I guess it works like this:
New Ricochet = HoloFlex read of skid-hook.
Used (20 games or so) Ricochet = TEC2 midlane read.