One more reason- my Bagman saddlebag support clamps onto the back of the saddle rails, and I couldn't install it or use it with the short railed "S" B17. The regular non S saddle had plenty of rail length to spare. It had about 1 1/2" MORE in rail length- that's a big difference.

But the biggest reason was that I kept feeling my saddle was too far forward with the B17S -felt like it was centered directly over the seat post, and it felt like I could never get 'behind' my pedaling- kind of like I was riding a unicycle.