I really dislike her voice. I'm not sure how much of it is the studio editing and how much of it is natural, but it sounds completely synthesisd and robotic to me - like there are two copies of her. It reminds me of a harpy.
My Immortal is also the worst song I've heard for many, many months. I really can't stand it. Just different tastes, I guess.
The one Evanescance moment I don't mind is the small part of 'Going Under where she goes 'Aayyyyyye-yaaaaaaye' (vague, but if you've heard the song you'll know the part), as her voice sounds natural for once - but as soon as that part ends, it's back to Dr Robotnik.
This is coming from someone who prefers female vocals almost exclusively 😉