I don't think UNC is under-rated or over-rated. In terms of placement an the quality of its students, it seems to be a pretty solidly #20-30 school.
I've lived in Chapel Hill for the year, by the way, and it's a pretty cool place. It's not super-urban, obviously... but there's enough fun stuff to do, the weather is awesome, and the whole place has a good laid-back, fun, sportsy, semi-intellectual vibe. I'd love to come back here some day and raise a family if I could find a cool job in the area (like being a prof...that would rule).
I don't think I would go there if I wanted to practice outside of the South, however. I mean, it may be successful in placing some grads in the Northeast or West, but if you want to practice in those regions, why not make it easier on yourself and go to BC, BU, UCLA, USC, or those types of schools?