Nice rational thinking, chigirl.
When you think about it, the 1-year program at Harvard (and Stanford too) seems to have been created more for the schools' benefit than the students. They can turn students in and out twice as fast and attract more students who will pay full sticker (30-40k for an education over one year vs. double that for 2 years). I think you make a good point, chigirl, when you say it seems Vandy might be more invested in you - seeing you as a scholar rather than a product. One year may seem great at the outset, especially if you plan on diving right back into the field - you can have a degree so fast! - but if you want to build relationships, get the attention needed to develop your skills, and stay in academia, maybe the 2-year Peabody program is better?
And, my two cents: I think the fact that there are so many threads here where people agonize between Vanderbilt and Ivy Schools/Stanford shows that Vanderbilt's name recognition and reputation have increased quite a bit in recent years.