Congratulations on these excellent admits.
Now getting to your question, it depends on your goals. If you want more exposure to management, duke(fuqua) seems to be more logical. I had applied to both these programs too. And if given the choice, I would have opted for Dartmouth for the following reasons:
1)Excellent placement record
2)Close-knit community owing to its small class size
3)The faculty, especially Mr. Ross Gortner, takes a lot of pains to ensure that everyone gets an internship and a job offer in their area of interest.
To add to all this, you have a scholarship(yes it isn't 40%, but it is still good enough). You'll even get the "IVY" tag, if that matters to you at all. Dartmouth's alumni network is very extensive and extremely helpful. I have gotten very positive and encouraging response from my interaction with their current and past students who've been very helpful. Go with your heart. I don't think you'll regret joining either of these programs.
Wishing you all the best!