Took my full 12 weeks paternity leave and have zero regrets
A lot of guys at my company only took 2-3 weeks which I get financially but man, those 12 weeks with my newborn were incredible. Got to handle all the overnight shifts so my wife could sleep, learned how to change diapers without panicking, and bonded with my son in a way I might have missed if I went back early. Already told my boss I'm not doing weeknight travel for the rest of the year. Career will be fine. These moments won't.
12 weeks is the sweet spot. You actually get through the chaos, figure out your kid's personality a little, and bond in a way that taking 2-3 weeks doesn't allow. Totally worth it.