I'm kind of mad at Rebuild for turning Rei's sunny smile into a subdued poker-face type cheek elongation. Rei is the original "silent girl" and what sets her apart from her millions of clones is that unlike most of them, she actually DOES have reactions to things. I think that's what makes her a good character; she can still scream and smile and things.
Remember Kharas, we're working with TEH REI here, not Yuki fecking Nagato. The original, not the cheap knockoffs.