I had to think about my response here quite a bit. So far, you've mostly received feedback about you, the risks, etc.
I'm going to tell you about the rewards. To put it in perspective, I have 2 daughters, 7 and 10. I just turned 41.
Unconditional love. There is nothing better than walking in the door after a horrible day and having a little person there, anxiously awaiting you with hugs and kisses. It can make EVERY day worth living. On the flip side, even your good days can be made better just by listening to them giggle and scream while they play with you.
My 10 year old is relatively intelligent and is now getting to the point where I can have logical and informative conversations with here about science. We recently started watching COSMOS together. I don't know what I love more, watching the show, or stopping it to explain a principal she doesn't understand and then watching her eyes light up when she gets it.
When your child decides to like something you're interested in, you've just discovered someone who will always be there to do that with you...even waiting in a line for an event. My older one got involved in FLL(First Lego League), it's a Lego robotics competition, you have no idea how happy I was to coach her team. My little one is so jealous that she can't do it, that she and I dedicate time to work on "her" lego robot.
There are hundreds of reasons to not have a kid and just as many to have one. Sure, throwing up in bed in the middle night sucks. But sharing their pride when they make honors in school, or sharing an interest/hobby with them is a fantastic feeling.
And you're never really ready. The question is if you're willing.