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.