::Sigh:: Rock is not a rushdown character, ANYONE will tell you that, he CAN rush, but his MAIN or PRIMARY strength is in zoning the opponent out.
He is a control character, He needs meter to dictate the pace of the match, and YES he is scary when he has stored meter, because of his very useful supers.
But your main question, what chars and grooves are problematic for P-Rock?
A-Sak, obvious reasons, CC, her s.HK and c.HK reach the same length so you’re playing a guessing game everytime you try to crack counter it.
CPK-Cammy, if she has meter, watch out, because she can combo into it by many ways, if she doesn’t she is still scary, because she can poke you all can with s.HP and s.HK and lk Spiral Arrows
and I’d stretch on a limb and say:
PK-Rock, It depends on who has the better game plan, better execution, better tactics, etc. because Rock is hard to get in on, he CAN get in on you and deal some damage and then zone your ass up when you eaten that 360 thorw breaked inot a Shine Knuckle. But Rock without meter isn’t as scary as Rock with meter though, nonetheless, Rock is hard to beat with Rock.
C-Sagat, His High Tiger shots (obviously) travel over your repukkens, and probably travel faster (HP Tiger Shot vs MP Repuken) and he has many ways to get to you, and when he does get in, he can take off a chunk of life with a simple combo and then he can force you to make your own moves, which is not a position that Rock wants to be in, but he can do fairly well in.
I’m forgetting many people but I dont have time to post them all now.