OK, so I've ridden two 20 mile rides so far on my new B68. I LOVE IT!!!!!
First- I got the non-S model B68 because I wanted the longer rails underneath so I could attach a Bagman rack for my largish saddle bags:
http://www.peterwhitecycles.com/saddlebag_support.asp
The B68S has shorter rails and shorter nose and not enough room on the rails to attach the Bagman.
The B68 and the B68S both have the same width in back for my sitbones, so that was not an issue. They are about an inch wider there than the B17S I had before.
The width is PERFECT- I can feel how nice my butt fits on the saddle now, instead of being sort of "perched" half on the back and side edge frame of the B17S.
Yes my sitbones are a little bit sore right now because the saddle has not yet formed to them- but I'm proof-hiding like mad and riding a lot. It's not nearly as bad as when i first got my new B17. Guess I have a "Brooks Butt" all broken in already.
The longer nose is not proving to be significant at all. The old B17S nose stuck out about 1" in front while riding, and the new nose sticks out about 1 1/2" and doesn't seem to affect anything differently.
But the very BEST thing I have discovered, even better than the width issue, is that the new long rails allow me to shove the new saddle way further back- about 1 1/2" further back than my B17S with its short nose and short rails did. It's Heaven! Now I have more leg power and I feel like I can get "behind" my pedals as I ride- it is SO much more comfortable! Now I know how men get to feel comfy all the time on their bikes automatically.
It's sort of like the difference between riding a unicyle and pedaling a paddle boat- exaggerated comparison but that's the feeling, getting way more power from my legs and feeling nicely stretched out and "behind" my crank. This back-shoved saddle made me bend in half just a bit more- but being on a Rivendell (where bars and seat are about the same height anyway) this did not feel bad at all- in fact it feels BETTER. I can just hunker down comfortably in the drops, scoot all the way back and spin up those hills now without burning out my legs.
I made better time on my ride today- faster in the high gears on the flats, faster up the hills and less tired, and just way more comfortable in general.
I absolutely LOVE this saddle!!!!! My Bagman saddlebag support fits perfectly on it too, with room to spare.