I'm an intern at Columbia, and I can share my thoughts. I would offer the preface that I am extremely biased in that I am happy at Columbia, and I really do love the program.
Regarding malignancy - I heard this when I was on the interview trail, and I heard it from applicants this year. I honestly don't know what it means because I think "malignant" can mean different things to different people.
One interpretation is that the program is full of gunners and residents aren't supportive of each other. This is flat-out not true. I feel like my co-interns are my family, and in the short time that I have worked with them I have formed numerous friendships that I believe will last beyond residency. To be fair, I think people going into IM in general are nice and fun to be around, but this certainly holds true for Columbia.
As far as support/autonomy goes, I think Columbia is structured to prioritize intern autonomy as much as possible, but the support is definitely there. If you feel like you need help, you ask a resident or an attending, and they are happy to help you. I have never heard of anyone getting shot down for asking for help. In my experience, residents take the quality of life of their intern as a point of pride; they want you to get out on time, and will actively work to make this happen.
One anecdote about support that sticks with me happened when I was working nights in the Allen Hospital ICU (an intern-run ICU at the smaller, community-style hospital affiliated with our program located at the northern tip of Manhattan). This is generally considered one of the most fun rotations of intern year. During the day, you are supervised by a 3rd year resident, and at night by a hospitalist. One of our patients was very sick, and there was an ongoing discussion about goals of care between the ICU team and the family. This night, the patient's daughter told the nurse she wanted to discuss further something that she had talked about with the day team, and the nurse relayed this message to me. I told the daughter I would page the hospitalist, and she should gather other family members, and we could have a family meeting. The hospitalist was in the ICU within 2 minutes, and we had a family meeting with 15-20 family members. Afterwards, the hospitalist told me he was happy that we did that because it was obviously helpful for the family. This is just one example: in my experience our attendings are always this willing to help you if you ask, but the program is set up to make you feel like you as the intern actually have responsibility.
Maybe "malignant" means we violate work hours? This is also not the case. I have not gone over 80 hours per week so far this year (it does happen occasionally), and I have only come close a few times. Our program director actually believes in the rules, he doesn't just see them as a constraint that he has to work around. Also, although our program is clearly front-loaded, the tough rotations during intern year are interspaced with numerous more laid-back ones (outpatient, geriatrics, elective, ambulatory oncology).
As to ancillary services in New York City, what everyone says is true: they are not as good as elsewhere. I'm perfectly willing to accept that our hospital does not run as smoothly as many in the country, and that as the intern, it is often my responsibility to make sure that things are happening. I draw labs rarely, but I do have to make sure that they are drawn. I don't transport the patient, but I have to make sure that someone comes to do it. To me, this doesn't mean that the program is malignant, but I do see it as a potential downside of the program. It frustrates some people more than others. Overall, I think it is good experience managing people and making a system work, but it can be trying, I'm not going to lie.
I believe our hospital does offer great medical care, and I would want my family treated there, but I think that this is so difficult to asses that I won't belabor the point.
I love our patients, hands down. We get a big variety, of course, being a tertiary/quaternary-care referral center. In the ICUs and on the floors, there are many patients from all over New York City and the surrounding area. In clinic, it is predominantly Washington Heights residents, who are predominantly Dominican and Spanish-speaking. These patients are friendly and grateful for the care you provide. Compliance and patient education is a challenge, as I believe it is in any Medicare/Medicaid-based primary care population. We obviously have access to in-person and telephone interpreters, but nevertheless if you don't speak Spanish, the language barrier could be a turn off for you.
Sorry for the lengthy response, but I'm passionate about the program.