If you choose to be reborn, you will not have magic powers, but you will unlock a status window and a skill tree that you can use to give yourself new skills and abilities and improve your physical characteristics.
You’ll get the same thing if you choose to be reincarnated, however, magic will be a factor. And the age of the world will be somewhere like 50-ish years before the full rollout of the industrial revolution, technology-wise. (minor clarification, you keep your current knowledge either way)
However, you will not be the hero or the chosen one. You’re just going to be a person with a perk.
You said “with your current knowledge still intact”. If that means I can know beforehand which things I’ve already invested in which didn’t pay off and those which did (and I mean relationships, careers, life choices, not necessarily money) that alone would be a massive perk. You want to give me physical perks on top of that, I’m not complaining. But the deal was already a no brainer.
If there isn’t knowledge remembered then I’m a bit ambivalent about which of the two. I think I might go for magic but if you strip all memory away I would have nothing to compare it to.
You would keep your memory. It’s just knowing that the Cubs won the Super Bowl in 2015 doesn’t really do you any good in a world where there is no Super Bowl, or if there is, then it’s played with dragons.