Below is a map of the two possible sites and their proximity to a verified Roman road of the time:
Khirbet Kana, some 6 or 7km north of the road.
Kafr Kanna, about 1km south of the road.

Map courtesy of www.jesus-story.net
Here is Nathaniel's1 contribution to a discussion with Philip regarding Jesus' birthplace:
And Nathanael said unto him, Can there any good thing come out of Nazareth? Philip saith unto him, Come and see.
-- John 1:46 (KJV)
The map shows where Nazareth is situated in relation to the road. It is roughly the same distance south as Khirbet Kana is north. According to Nathaniel's comment, Nazareth was clearly looked upon as an inferior place to live -- by the residents of Cana at least.
Life in towns like Nazareth and Khirbet Kana would have been much more traditional than places like Cana, since very few travellers passing though the region would have taken the trouble to pay them a visit. Not so Cana, though. Being only a fifteen minute diversion they would have had many visitors, bringing with them money and news and different ways of life. It follows that residents of Cana would view themselves as better-off and more "progressive" than those in towns like Nazareth and Khirbet Kana, who would have been thought of as backward and unsophisticated.
Based on Nathaniel's comment (and its implications), the traditional site of Kafr Kanna still remains the most likely candidate for first century "Cana of Galilee".
Notes:
- John 21:2 provides evidence that Nathaniel was a resident of Cana, and so his perception about Nazareth was likely not uncommon at the time.