I own both (in damier ebene), and I use the NF as one of my daytime/weekday bags, and the Eva when I am out with friends, at casual or semi-dressy parties, at the movies movies or any other time when it is not convenient to carry a big bag around (keep in mind that if you wear sun glasses, the case will take up all, or almost all, of the room in an Eva. I found that a little disappointing, even though I love the bag.)
The NF gets more usage, because during the day I tend to carry a lot. Both are great, useful bags. So the question would be: do you tend to carry a lot of stuff most of the time? If so, go for the NF. If not, go Eva.