Honestly, this might just be my favorite Christina song ever. Her vocals are on point, but she's using her talent for good here. Rather than overloading the performance with annoying melisma and forced technique, she reels it in, allowing for interesting subtleties and genuinely affecting emotion to shine through. It's sad that such an amazing ballad had to flop because it was associated with quite possibly the messiest pop star era of the decade.
Its her masterpiece.