Who cares if she's a gem? Assuming an AWALT mindset is likely the best sexual strategy.

For some things, such as the level of respect I have for a new business partner, I've found it most beneficial to start out neutral, and have them prove themselves either way, even if the prior distribution is not 50/50 (deserving of respect vs. disrespect).

However, with girls, assuming that NAWALT is a far riskier proposition than assuming AWALT.

If you think "she may not be like that!" and you're wrong, those risks far outweigh the risks of assuming AWALT and being wrong.

If you assuming AWALT and after 50 years of marriage you realize that you were wrong, that's a first-world problem right there. If you assume NAWALT and after 10 years of marriage you're wrong, you're most likely broke and broken.

It doesn't matter if only 90% of women are like that. It's a more rational mindset to assume AWALT and give her the chance to try to prove you wrong, since the risks far outweigh the rewards.

If you get married, even if she "isn't like that" or whatever, assuming AWALT would mean that you choose to get a prenup, you choose to keep yourself vigilant and good looking, you make a distinct effort to keep her level of interest in you, both in your personality and physique. All of these are good things.

When hooking up with new girls, I can attest that it's a far better (more successful) mindset to assume AWALT.