I am definitely swayed to the "having kids' earlier, especially having done it and having this story to affirm it. As you know we are on a year long adventure right now - early 50s, no kids. It's awesome!
My son is 27 with a nearly two year old and his wife is finishing a politics degree and working in policy for super company. It's actually a good way to stay grounded and focused ... You have the energy for a career AND a kid.