I went with white because I already have a few black-dialed Rolex, and because it's a bit more legible. I love the way it looks in the sun and by the sea, too.
They're both good, though, and I don't think one choice is more correct or better than the other. As with every watch-decision matter, it's best try them both in person if you get the chance. I'm sure I would have been happy with either colour. Swapping dials isn't something I would do frequently on a chronograph due to how tightly the central seconds has to be fitted, but the option is there and it's not too difficult to source an alternate dial for a 116520 — so it's not like you're committed to the choice for life.
No regrets on the white dial so far, however: