Thanks for your insight and suggestions! You've helped me confirm what my rear end was telling me last night.

By "could be more comfortable", I meant that by rear is tired and ready for a break after an hour or so. A few minutes of walking a stretching, and I'm fine to get back on the bike. The discomfort goes away very quickly. Good point, Grog, about a sore butt also after sitting in an office chair.

After last night's experience, I'm wondering if I just need to give myself more time to adjust from my hybrid seating position to the road bike seating position and to adjust to riding longer distances before experimenting with more saddles. I certainly know what UNCOMFORTABLE is now and can live with the other saddle for a while.