I think Liza and I are cut from the same cloth so to speak, although I have admittedly not tried the Castellis. But I share many of her opinions, having gone on a bit of a quest last year for new shorts. The Shebeest Ultra D's chamois has quite a bit of sit bone padding. I, personally, didn't love the the overall bulk of the chamois, however, and didn't find the cut particularly flattering. I liked the Craft Master short's chamois, too. The rise was just a little too short for my taste. I ultimately settled on the Sugoi RS short. I really love the material and the chamois's concentrated density for my sitbones. I agree with Liza that the density in the front it a bit less. I use a Terry saddle with a cut out, and that combo seems to work for me. I have a pair of PI Microsensors (2007 model). They're okay. Again, like Liza, I'm indifferent to PIs. I used to really like the Ultrasensors, but they widened the chamois in the front for 2007 and that didn't "sit" well with me.
At the end of the day, finding the right short requires a bit of trial and error unfortunately. I still have a pair of Hincapies that are almost brand new that need a good home.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher