Inwood is fabulous for kids and there are lots of them up here, some attending public schools and some attending posh private schools further downtown like Dalton.
You want to live west of Broadway and above West 207th ideally -- there's a northwest wedge of Manhattan Island that is loaded with parks and just a few residential streets with buildings no higher than 8 stories so lots of sky and not too much population.
THREE public transportation options exist up here:
A Train (last stop West 207th and Broadway so there is always a seat at this station)
#1 Train with 2 stops in Inwood: Dyckman, West 207th Street, and West 215th Street
BxM1 Commuter bus $6 each way $3 for seniors and worth it -- tour bus with no cell phones permitted -- quiet, clean, comfortable. In Inwood it picks up in front of the 2000 Cleaners on Broadway between West 204 and West 207. It brings Inwood folks to the east side of Manhattan with drop-offs beginning on 96th and Lexington all the way down to 34th and Lexington.
Then there is also First Class Car Service.
I've lived in Inwood since 2003 and lived in midtown over 30 years - THIS is my favorite Manhattan neighborhood, often called "Upstate Manhattan" by realtors for all its parkland and wildlife.
The only demographic who might not be happy up here is the 20-something party animal as it's too far from late night partying -- VERY quiet after 10pm at night -- so party living downtown first and then move up here when you're ready to settle down a bit.