Okay, I'll chime in. I went to UNC for residency and fellowship. I had a terrific experience there, met some awesome people, and learned a ton. The program is well balanced, and over the years grossing responsiblilites have actually diminished some. 1st years now have protected slide preview time, and to my knowledge are not allowed to gross after the PAs leave (which is around 4:30). 2nd years gross an entire bench when on Surg path, and 3rd and 4th years just do "one or two interesting cases a day" when on service.
We used to get a solid block of protected board study time in the Spring of 4th year, that may be changing some, I'm not sure. No one has failed boards though since I can remember. I don't have a ton of knowledge on Duke's program, but from what I've heard UNC is a bit more relaxed. Anyways, great place to train, but there are a ton of great places to be, so just pick one and go with it.