You get speed. For animation, doing a dom diff each frame is really slow. D3 is way way faster. For data visualization, d3 has a lot of well built extensions.

You get speed. For animation, doing a dom diff each frame is really slow. D3 is way way faster. For data visualization, d3 has a lot of well built extensions. I tend to go in the other direction, I use d3 rather then react for the rest of the page, so I don't have any issues with integration.