Point well taken, amyers2002.
RG tells us how easily the core revs up. Most bowlers can use the lower RG balls with huge success when the cover is matched up with their conditions because the vast majority of us are not 450 rev rate guys.
I'm no THROBOT, and feel most bowlers wouldn't have any difficulty using the above listed balls. The best replacement for the Fanatic is a Fanatic, but since they are gone...