OK, so science has identified a ton of other senses that humans have beyond the basic "five". We have stuff like thirst, hunger, thermoception, pain, balance, the passage of time, the position of our body parts in relation to the others, etc. Heck, apparently we even have the ability to sense magnetic fields, though we're kind of terrible at it in comparison to birds.
Obviously, Scadrians haven't figured out that they have more than five senses yet, but the question remains what sort of effect (if any) Allomantic tin would have on those "extra" senses. (Obviously Feruchemical tin wouldn't do anything, because you have to know you have a sense in order to store it into a metalmind.)
So, specific question: I chalked the sense of balance up as something that tin could enhance, and one of my beta readers came out and said, "Hey, shouldn't that actually be pewter that would do that?" And my answer was, "I don't know. Consult the boards!"