Nashville Best (2 nghts): Margot, Mambu, Zola?
I would go Margot, Zola, Mambu. I have only been to Mambu once for lunch and was not impressed. I prefer Margot to Zola, but I think it's a matter of food preferences. Margot is more influenced by French bistro cooking, while Zola seems to lean more on Spanish cooking. I find Zola offers more bold flavors and combinations, while Margot is more restrained and refined. Margot is definitely "cozier" than Zola, but I've never felt cramped in there. Enjoy.
I'd rank them Zola (best), Margot, Mambu for food, and Mambu (best), Zola, Margot (last by a long shot) for ambience. Some people swear that Margot is the most romantic place in the city, but I find it loud, with tables right on top of each other, unless you can get a table upstairs. Mambu is where I go for my own anniversaries, Zola would be my second choice, but you won't really be sorry if you go to any of them.