It is kind of interesting how the Sora shifter is the only one with the Campy-style thumb shifter, which I personally prefer. Sure the higher-cost shifters may shift "smoother" or whatever subjective measure you want to use but the physical difference is undeniable. I have Tiagra on my daily bike and a Campy setup on my blingier ride - whenever I go back to the Tiagra I wonder why Shimano didn't go with thumb shifters down the line. My guess is they needed to differentiate from Campy or vice-versa. I can't even "upgrade" my gf's ride with my old parts because she prefers the thumbs as well.