Comparing Statistics PhD Offers

[StatNerd100]

Hi everyone! I'm trying to decide between statistics doctoral programs. My top choices at this point are Duke, the University of Michigan - Ann Arbor (with a fellowship that exempts me from teaching/service obligations for my first year and two additional semesters of my choice), and NC State (with a fellowship for the first year). Duke and Michigan offered comparable stipends. NC State's stipend was slightly lower, but they suggested that they could try to match other offers. I'm interested in the research at all three schools, even though there are major differences. I am finishing my Bachelor's in math, and I haven't yet delved heavily into any specific area of statistics. However, I have really enjoyed that probability theory classes I've taken as well as the applied statistics and computer science projects/research that I have undertaken. In essence, I could foresee my future research taking a variety of directions, so this is less of a deciding factor (at the moment). In terms of my career goals, I have always wanted to become a professor, so I hope to pursue a tenure-track faculty position eventually after I finish my doctoral studies. 

As of now, I'm leaning towards Michigan, Duke, and NC State in that order (which is very tentative). Michigan's fellowship was very appealing, and they also offered to cover relocation expenses and dental insurance. I might be biased because I am originally from the Midwest, and it's honestly my favorite part of the country (unpopular opinion). The weather is not a problem for me, but the isolation of Ann Arbor is slightly detracting (whereas the proximity of SAMSI to NC State and Duke is very appealing). I just visited Duke and NC State, and they both had beautiful campuses and very friendly faculty and students. However, I was slightly concerned that NC State seems to have a high percentage of domestic students who fail the qualifying exams. 

My questions mainly are:

1) Is there a major difference between Duke, Michigan, and NC State in terms of rigor and/or potential for landing a post-doc at a strong program?

2) I'm also considering offers from lower ranked programs: UNC Chapel Hill, Purdue (with a fellowship), Emory (biostatistics), UC Davis, and Texas A&M. Is there a notable difference in the prestige of these programs compared to Duke, Michigan, and NC State? How accurate/reliable/useful are the US News rankings?

Thank you so much for any input!!!!!!