Having read Luminosity, but not Radiance:

If you set out to write a story in which someone tries to be rational and it absolutely backfires, you have succeeded. The majority of Bella's problems are caused or aggravated by her own insufficient luminosity and her perception that she is better off in that department than she actually is. In particular, she doesn't seem to gain any benefits from her above-average rationality at any point after she has fully transitioned to being a vampire; many of her problems are caused by overestimating her abilities and insufficiently analyzing her decisions to keeping things secret. In short, she lives for almost the entire story in the valley of bad rationalism.

Since that was not the stated purpose of the story, I don't think I can even reasonably consider this rationalist fiction. Which is highly disappointing.