From the website: http://www.takamine.com/?fa=searchbody

The NEX body will be louder, but, for me, more uncomfortable. So on that, I'd choose the dreadnought, for its comfort.
If you can, make your way to a store that deals Takamine, and try out each body style. That'll be the best way to figure out which one is better for you, because from what I can see, the body style is the only thing different.
Okay, I've tried guitars out of the two styles before, and I didn't notice that much of a difference. I guess there's only a bit of difference between comfort and loudness?
A dreadnought will be louder and have more bass. the NEX body style is tonally balanced better for vocals. Definitely try some Takamines out.
I want you to put on your pretty summer dress
You can wear your Easter bonnet and all the rest
And I wanna make love to you yes, yes, yes when the healing has begun
-Van the Fuckin' Man