Been gettin crazy into Valkyria Chronicles 2, that's another amazing game recently and I'm pretty sure it got great reviews, but because it's on PSP it's only more evidence how "generation"'s utility as a classification is eroding.
I can't speak for Brink (I think it may only have a slide button) but in Killzone the cover system is 1) more immersive (actually leaning out and aiming at an angle) and 2) more functional to keep popping out than strafing from behind or crouching then standing is.