The negativity surrounding Columbia seems kind of unfounded and based on previous reputation that lags behind changes. A chief i spoke to acknowledged the malignant reputation and suggested it was probably due to 1) the old PD who was very distant since she worked offsite 2) people have complained about relief later than 5 on some/not all non-short call days. The first one is no longer an issue b/c the new PD is, if you interviewed i'm sure you'd agree, very warm and attentive to the residents (residents, one of which is a family friend of mine have corroborated this). The second one it seems is honestly a symptom of being an NYC program... non-short call days just won't always end promptly at/before 5 due to rooms going late at these busy hospitals and how that affects the relief system. Sinai and Cornell residents have said they're incredibly busy too. I guess NYU is the exception here, but not even by that much. I feel like I was really confused at the discrepancy btwn SDN reputation of Columbia and what I actually heard during my interview so I want to do my part to help update people.
Reputation nationally literally doesn't matter when comparing the big 4 in NYC. They all match great and will all give you connections to get to where you need to go fellowship-wise or put people into great PP/academic gigs.
As for subspecialties, if you just look at the resources at each hospital you will get your answers. Peds is better at Columbia b/c of CHONY, transplant is good at Sinai and Columbia (sinai has no lungs tho), Regional at Cornell (HSS), Cards at Columbia (Shanewise is there) and Sinai, Pain im not sure about tbh if someone wants to chime in abt this. But honestly, it doesnt REALLY matter. You're not gonna like, not be able to become a pediatric anesthesiologist just because you didn't go to Columbia. All these places are DOPE residencies and I'd be grateful to be at any one of them.