We had our first when we were 30 and the second at 33, then "snip snip" no more kids for me.
It has worked out very well for us. By the time we were 30 we were reasonably stable, financially secure and were able to focus energy on our kids instead of building a career.
On the other hand, if I had to do it again, I'm not sure I would have kids at all. I love my kids, but there have been times when I wanted to change directions in my life and I didn't have the freedom to do so. 
A few years ago, I really wanted to take a year or two off and bum around spending some of our money, but it wouldn't have been in our kids best interest to take them out of school for a year or more. 
A few years before that, I would likely have left my wife during an especially difficult time. Out of respect for our kids, I couldn't leave, so I am still in a marriage that I don't have any passion for.