As a reminder, you can now purchase every common and uncommon crystal from the base game, plus Amazonite, from the computer, which makes the crown even more powerful.
I wasn't aware of this! Thank you for the info
Thirst in my vamps is an issue that can't be perked away, but now I have the perfect answer.
If the crown is worn constantly, the crystals don't last much at all -- and when they break they tank one of your needs, even if you have the vamp perks that should prevent it (I keep some moodlet solvers/books of life around in case that happens). You'll know the crown is about to break when the lights turn orange, then you can remove the crystal and slot a new one. What I have been doing is equip the crown for a few seconds when their thirst is low and then remove it; it won't completely fill thirst, but gets the bar almost full without drinking 752863 plasma packs or losing reputation from a deep drink.
This object is so OP it's a bit nuts really. I can't see me ever using it but it'll be interesting to see how others plan to use it.
The crystals break
very fast, which makes it not as OP as I initially thought; still useful for some crazy bouts of skilling I suppose, but not something to be worn constantly (it also makes other sims point and laugh at the wearer, which was hilarious at first but eventually became tiring).
Hematite, however, is incredibly powerful. Worn to work by a test sim got her from average to excellent work performance almost instantly. It then broke halfway through her shift and tanked her fun, but a good mood before work and the carefree reward trait would prevent any performance loss from this. And, as DarkWalker pointed out, you can buy it from the computer now, so no more gambling with the Wishing Well for fast promotions