I'm a 4th year at Duke. I'll give you my opinions of the advantages and disadvantages of Duke's curriculum if this will help you in making your decision.
Advantages
1. Get lecture done in one year. My husband goes to UNC's med school and he and our friends in his class were so jealous we only had to be in the classroom for one year.
2. Rotations a year early really make applying to residency a LOT easier. Unfortunately, not everyone decides early on what specialty they want to pursue. Imagine being at the end of your 3rd year and being unsure, or just deciding at the end of your 3rd year. If your specialty of choice happens to be a competitive field, it's going to be tough to get any research under your belt after the fact (research isn't necessary for all fields but it helps. See #4).
3. Early electives. I know of several schools who don't give any electives until 4th year, or at the most give one. If you don't want to pursue one of the core rotation fields, how are you going to know what to do? Duke not only does its rotations a year early (giving you an extra year to figure it out), but we do three electives in the 2nd year.
4. Research/Dual Degree year. First, research looks really good on a residency application, especially substantial, dedicated research where you actually published/presented at conferences. Duke gives you an entire year to be involved in research and beef up your application without extending med school. Furthermore, the mentorship at Duke is excellent. I'll be honest in saying that my step 1 score was fine but not amazing...without the third year of research (and my clinical grades, an issue raised by another poster) I would not have done as well as I did in residency interviews/the match. And if you don't want to do research, you can do a dual degree in pretty much anything (MPH, MPP, library science, medical humanities, etc). Duke is extremely flexible for its 3rd year. Plus, it's a much, MUCH easier year.
5. Step 1. More time to study for it, because you can take it anytime during your 3rd year. So you can study a little bit every day for months then take a few weeks off for dedicated study time.
6. 3rd year funding. Lots of funding/scholarships available that are >$20,000.
7. Lots of opportunities to go abroad if you want, even in the 2nd year.
Disadvantages
1. The first year goes faster, and it can be stressful at times. But, you don't go into quite as much detail as some other schools do (you'll learn what you need to learn eventually, sometimes it's on the wards 2nd year, which actually helped it stick for me than just reading it in a book). Besides, what med school isn't stressful?
2. Given #1, Duke students aren't quite as well prepared for the wards as other schools who take 2 years to do the basics. But, the attendings/residents know this and they grade accordingly. Many of us get honors in our first rotations. If you learn better by doing rather than reading, this can be advantageous for you.
3. Step 1. You are further removed from the basic sciences, making reviewing more difficult. It does help some that you've already had a year of clinicals, but I personally had a bit if difficulty separating out how I needed to study for step 1 (vs step 2, the clinical exam). But that's just me, and I know plenty of my classmates who killed step 1. Plus, as I mentioned in #5 above, you have more time to study.
4. Because of the research year, your 4th year will not be as vacation-filled as at some other schools. You'll still have mostly electives, and depending on your 3rd year you can have up to 2 months completely off (which is still less than at some schools that give like 4 months off). But Duke does give 5 weeks for Christmas vacation during 4th year so you can interview without having any other obligations. And by the way, I'm done with med school classes TOMORROW (April 2nd), so it's not too bad
. But it can be less, so be aware.
Anyway, there's an overview of how I see the pros/cons of Duke's curriclum. I hope it helps. You're choosing between two great schools, and choose the one that you feel you'll be happiest at (in other words, go with your gut). Best of luck!