Hi Walden,
You raise a very good point, we plan to add more details to improve the transparency.
We're also talking about identifying which camera was winner/loser in different categories, e..g maybe the D300 takes better pictures but the S90 is better for travel (since its small). Thoughts?
The way Snapsort picks the winner is by adding up the scores for pros and cons of each, whoever has a greater total is the winner.
The current site has a bit of an issue, point and shoot cameras often beat out SLR cameras (as in this case) because there are more pros for them, e.g. point and shoot cameras score well on "macro photography", "zoom" since they have lenses.
We're close to releasing an update which improves this, so that when two cameras are compared, the winner and loser is chosen based on features they both have.