I absolutely LOVED JFK when I rotated there. I'm not sure if it's true that you have to do a rotation to be considered for a spot but I do know that most of the residents I rotated with had done a rotation there.
I think because it is a small program, Dr. Cuccurullo is very committed to maintaining the best atmosphere possible so people who rotate there and do well and are liked by the residents usually do well in matching there. that being said, if your personality doesn't mesh well with the program's overall feel, then rotating there will count against you.
If you are interested in matching there, I would at least spend a day or two shadowing an attending and meeting as many of the residents as possible (only 4 per year) AND spend a good amount of time and effort on your personal statement.
In terms of cush-ness, I think it is more cush than many of the high powered academic residencies. For example, I remember residents getting paid to do weekend admissions and note writing. they also got paid for covering local high school/middle school games. They also went out with their attendings a lot and hung out with each other a lot. (When I was there, a bunch of the residents decided to sign up for group golf lessons) They did not take in-house call, they did not have peds call (although they also rotated at Mountainside, unlike Kessler residents, they did not do much in-patient peds or take call there - can't remember if Kessler takes call...)
In contrast, at least at my program, we are NOT paid to do weekend note writing and admissions (between 6-14 per day split btwn 2 residents). we carry between 8-20 patients per resident. (average about 16-18) And we definitely have late admissions, and sicker admissions. (LVAD patients, post-transplant, severe burns, etc etc.) We are the first responder to codes since we are a free standing rehab (need to know out ACLS and PALS), and we cover 150+ patients including peds patients when taking our in-house call. I believe Kessler and Baylor were similar in their workload and responsibilities.
other positivies about JFK: Cuccurullo takes great pride in her teaching abilities (she is the author of the board review book) and all their residents have scored in the 90th percentile and above in recent years. Dr. Uustal, the P&O guy is one of the best P&O docs I've met, he teaches the P&O section of the Kessler board review course, and he is one of the nicest people I have met. Dr. strax the chair is a past president of the AAPM&R and he is a very inspirational person. (has CP got through NYC public school system, etc.)
Defintiely read through old threads about JFK for more info.