I ride a Terry Zero X on my TT bike. I like it and works well for me. I do 95% of my riding on that bike and do rides up to 5-6 hours. I do find when I do short hard TT I need to remind myself to push my bum back or I have this habit of getting small tears in my private parts.

I have thought of getting a smaller harder saddle as my bike fitness improves I seem to like smaller saddles. When I got my new Orbea last month I test rode it with a Terry Butterfly which I used to ride a couple of seasons ago and it felt like I had a wad in my crotch...swapped that one out for a different saddle.