I think "natural" feels right on a touch pad but, I have a standard/wired KBM setup for working and a wireless keyboard with "touch pad" for sitting on the couch. That "touch pad" registers itself as a "mouse". OSes let you pick different scroll directions for mouse and touch pad, not specific devices. I have to switch manually when it bugs me enough. Just can't win. There is no perfect keyboard. Someone please prove me wrong.