Noomi's got far better screen presence and acting ability. She's also an actor that can convey genuine strength in dire circumstances, unlike Daniels who either seems unconvincing or just looks cute and teary. I feel like Noomi was wasted because she is such a good actor and it was criminal to just toss her away like that. There's also the dynamic between her and David to consider, which could have built to a great crescendo over the course of the films. I love Covenant, I consider it one of the best Alien films in itself, but it was a mistake to totally get rid of Shaw.