I've had my eye on this jacket for a while for my daughter, who is 5. Overall, I am very pleased, and she looks just adorable in it. So that it would fit her next year, I ordered a size larger, thinking it would be totally fine as others have said it runs big. What I found was that it really was not very big on her, and I am hoping to get another year out of the small that we ordered. She normally wears a 6, and is tall and thin. Though I have read otherwise, I have found with my kids, all of whom are tall and thin, that the children's sizes do not run very big through the body and you need to size up. Also ordered the Moondoggy for my 11 year old son in a size large (he normally wears a 12/14). It was so small on him, I gave it to my 8 year old son, and it just fits him.
If you're looking at the Gotham, buy it. You'll love it.