Since the Shift has some particle mixed in with the pearl cover, it should read a little earlier and be a little smoother than the N-Sane, theoretically. You may be able to utilize both by changing the covers -- keep the N-Sane polished, knock the shine off the Shift (2000 grit maybe?) to give you a smoother reaction with more midlane. When one isn't carrying, you can switch to the other, play the same general part of the lane, and get a different angle to the pocket.