the difference people should care about is presence/absence of rumble
Yes. It's not like the swinging and balancing or even the horse riding in this game are great fits for the sixaxis or anything.
So are they saying that the PS3 version currently has slightly better textures but the 360 has a slightly better framerate? (they're being examples of the different things the two games have going for them)
Well, it'd be a significant step up from the aberration that was Double Agent on PS3, if true.