Shouldn't it be the opposite? Sure, everyone appreciates some improvement but if you were being a fan of something or someone you need to hinge the liking on something tangible and quantifiable, much like Siri or Retina Display. The viral publicity and urge to buy is centered around that unique point that you will discuss with your friends. "Check out! it is faster!" doesn't seem to be as viral as "Siri, set an alarm for 5PM" to me. But again, my views are obviously biased as I am a techie.