For those who are nervous about Fizik's carbon rails:
So last year, I pulled into a parking garage, completely forgetting that my bike was on the roof rack (trunk racks FTW by the way). I hear a bang as the car lurches down, then it makes a horrible sound like it bottomed out. Horrified, I get out to see what happened, and inspect the damage. The saddle, which was tilted down about 30 degrees due to the fork mount, hit a concrete beam at about 4-6" from the back end of the saddle, and slid along the top until it cleared the structural member. The impact moved the roof rack back about 6", bent the rack a bit, knocked my one bolt seatpost out of wack, slid the saddle rails back a bit in the clamp, and scratched the hell out of the microtex upper. The rails, however, were still intact; surprising, considering it absorbed the entire impact. Rather than sulk and turn home, we decided to ride anyway, and then replace the saddle before the next ride, just to be safe. I never did get around to buying a new Arione, and it is still just as solid underneath my 175 lb arse as it was the day I bought it.
Impressive structural rigidity aside, I have to say that I prefer the Arione CX with Kium rails on my other bike. At least compared to my 2007 version of this saddle, the CX Kium is $100 cheaper, has a lower profile, more dense padding, and an ICS mount for saddle bags.