Granddad is a retired police officer and former police commissioner who has plenty of "Back in my day, we just beat the crap out of them until they confessed" stories.
Dad is the current police commissioner who does an admirable balancing act between the various personalities in his family (see the following). And, you know, running the NYPD, dealing with politicians and the media, that sort of thing.
Older brother is a police detective who takes after Granddad; also, he spent two tours in Iraq with the Marines. He is married with two kids.
Younger brother is a Harvard Law grad who decided to make a career as a cop. He's so by-the-book that he probably writes the editors love letters. (You can imagine the sibling arguments with older brother.)
And, older sister is not quite in the family business: She's an assistant district attorney who always seems to be explaining to older brother why the DA won't press charges (yet). She is divorced and raising a teenage daughter who brings in the youth perspective.
What's unique?
The family is Irish Catholic. Religion doesn't play a big role in the series, but we do see the family praying together before meals, and at times Dad seeks advice from a priest or cardinal (it's NYC).
Granddad is a vet - Korean War. Dad is a vet - Vietnam. And, as mentioned, older brother is a vet.
Balance: Generally, there is a real balance of viewpoints. Not always: There are a few episodes where it's not quite balanced, and one where we get outright preached to (we heathens!). But generally, it's probably the most balanced series I've watched in a long time.
There are six seasons on Amazon Prime for free. I recommend it, if you like cop shows, or family shows.