I interviewed at the Columbia program. As with any program, it has its good points and bad points. There is NO trauma and they are weak in peds and plastics. Furthermore, NYC is incredibly expensive. Residents are given a $3000/year housing stipend, which, according to one resident, covers about a month and a half of rent. The program also appeared to be very inbred. Half or more of each year's residency class had done med school at Columbia. Ancillary services are terrible - apparently it is not uncommon to see interns wheeling their patients to x-ray. Two lab years aren't required per se, but everyone goes into the lab.
Having said all that, Columbia is very strong in cardiac/thoracic and colorectal. All the residents seemed happy and said they operate early and often. They actually average 1500 cases/year, which can be perceived as a negative. And hey, it's Columbia, an ivy league school. You aren't going to go wrong with having that on your resume if you want to become an academic surgeon.
Can't comment on UNLV or Jacksonville as I didn't interview there.