No one?

The Pro is 2 parts solid, 1 part pearl.
The SAY is 2 parts pearl, one part solid.
Both are hybrids.

The Locos were stronger than the Shout/Scream combo.
The Hustles are stronger yet than the Locos.

I had 3 different Shouts drilled 3 different ways; I just couldn't get some backend from them even when I used 90 degrees of rotation. It was a urethane ball reaction almost no matter the surface or drilling. I had one Scream and I couldn't find a good surface or a workable reaction on all the different light oil patterns I bowled on; many other light balls were more consistent.

After all that, I kind of gave up on RG's HP1 line. The Hustles look promising, but for slightly heavy oils and for people with more ball speed than I have, on light medium to almost medium oil.

Charlest, I'm much slower, 15.5 mph, and for me the shout was a miracle worker.  Could play the track when the shot was fried. Loved it. Funny how were so far apart!

I'm really leaning towards the PRO Even though i wanna buy the SAY.

It might have been the pattern or oil as well as the amount. Plus I've had some physical problems the last 5 years that's caused irregularities into my game.
I saw so much potential in the dark green/light green Shout (2013) that when I couldn't get a good reaction from the first, I sold it and bought a 2nd one, using a pin over ring drilling which is my flippiest drill. Still almost no backend. On top of all that, my usual releases fosters a strong backend and I usually have to use smoother drillings.

All I can say is I gave them a more than fair shot.

FYI BTM seems to find the SAY more useful even thought the PRO, while being smoother, hooks slightly earlier and smoother than the SAY. BJI found the same tiny difference between these 2.  Good luck if you try one of them.

Oddly, I'm having much better results with sister company, Storm's, Ride and Tropical Breeze (now Tropical Storm, same ball). In fact, they've become part of my regular arsenal.