Just finished a stay with young kids. Exceptional by all accounts. They guaranteed adjoining rooms in advance, which were at the end of the hall (02/03 combo). This was two separate rooms connected by a front foyer. I had to push for this via email in advance, as we couldn't risk this with the age of our kids and had no choice by to cancel if it couldn't be guaranteed.
The service was amazing - doormen knew our kids by name, the front desk agents always said hi to the kids and made them feel like royalty. Housekeeping was amazing - we have two kids with opposing nap schedules, so housekeeping window is tight - they were always there within 15 minutes of when we called. The Ritz Kids check-in was great after a long travel day - the Skittles were greatly appreciated. The area is great - easy access to subway, and we spent a lot of time at Madison Square Park. I am also working on a file where the corporate rate was fantastic, which certainly pushed us towards this hotel.
Nubulez and Zaytinya were fantastic, and everything about this hotel felt first class. The rooms are really large, and the bathrooms are absolutely exceptional. A crib easily fit in the shower which made a great room for our baby.
If you have young kids, there is a sushi place that is a block and a half away called Kaiten Zushi Nomad. The drinks come on a robot and the food comes on a train - the kids love it, but more importantly, the food all comes within minutes, which is great for tired kids, and there are tons of food options. Not winning awards, but very decent food. We ended up feeding our kids there every night before the nanny came over so that we could go have our own parent's nights out. We booked our nanny through artistbabysitting.com which was a great experience. They charge $25/night to book, and the nanny was $35/hour plus cab fare home (about $40/night). The Ritz wanted considerably more to arrange and we had a few friends recommend Artist Babysitting.
Sidenote: There is an app called InKind - I have NO IDEA how they make money but all of the F+B establishments in this hotel use it. You can get a $25 off $75 at both Zaytinya and Nubeluz (just go to their websites and the offer will pop up), and then you also get a whole bunch of cash back on every purchase. It often felt like we would get a $100 bill, get $25 off, and then get $25 in cash back for our next purchase. Worth downloading.