To me, there's a subtle difference between Porter type pressure and Rios type pressure. Porter is a bit of a swarmer. He bulls in non-stop, and has the power to get your attention if you're not ready for the swarming. Rios is more measured in his aggression. He bulls forward... but is slower and easier to measure and counter. Just because Brook didn't look comfortable at times against Porter is by no means an indication he'd have the same trouble with Rios. I think (and hope) Brook handles Rios comfortably.