I don't ride as far as some of my fellow Clydes, but I do know that what may work great for some is pure torture for others. My rear end, I discovered, is absolutely happy on a Fizik Nisene Gobi saddle. I hope that translates to an Arione saddle, as I'm trying that next on my Road bike.
I have a Selle Superflow SLR on my Mountain Bike (that I use to commute on, at least 3 days a week, for 6.5 miles each way), and while it works fine for those shorter rides, I start feeling it at the 9 mile mark--maybe I need to get used to it, but that's where it stands.
My current Selle Italia Max Flite is very much in the same boat as the SLR Superflow, but I haven't take it on a proper long ride yet.
I really am curious at about the Selle SMP Pro--I really want to try one soon (maybe I'll try to buy one and decided between it and the Arione).
If worse comes to worse, I may have to fit a Gobi to my road bike too...