Sheebeast Ultra D

[VeloVT]

Have you tried the Shebeest SSS short? The chamois is a little softer/less dense than the Ultra D chamois, but it's quite similar.

Also, I would try the Terry Bella short if you haven't -- the chamois is quite similar to the Shebeest shorts.

You might try Castelli shorts too. Both the Kiss chamois and the chamois in their more expensive shorts are thinner than the Shebeest chamois, but like the Shebeest chamois they are flexible and not diaper-like. I find them to be more cushiony than the RS chamois too (I have a pair of RS shorts and my reaction to the chamois was similar to yours). The more expensive Castelli chamois is not thicker, but it is denser. Castellis are my favorites.

[Crankin]

I mostly wear the Terry Bellas (also have the silicon gripper, no elastic), but a couple of years ago I bought a pair of the Ultra Ds. I like them, but only use them on rides that are +40 miles. The chamois is a bit thick for shorter rides. Then, I forgot which ones I bought and ordered some SSS shorts. I also like those, but I find the chamois narrow in the front, where I need padding. Hence, those get worn on short rides.
I did wear the Ultra Ds on the one and only century I've done, with no issues.

[tctrek]

You might try Castelli shorts too. Both the Kiss chamois and the chamois in their more expensive shorts are thinner than the Shebeest chamois, but like the Shebeest chamois they are flexible and not diaper-like. I find them to be more cushiony than the RS chamois too (I have a pair of RS shorts and my reaction to the chamois was similar to yours). The more expensive Castelli chamois is not thicker, but it is denser. Castellis are my favorites.

+1 for the Castelli Kiss chamois.. by far my favorite for any length ride.