For me, WSD on the 2006 Bianchi made a big difference (I have short legs AND short arms. I need a shorter top tube). I really think there's no one conclusion about this, and that you just plain have to test-ride both and not let any store person talk you into anything that doesn't feel right, period.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks