Your assessment is the most astute observation I've ever read about what a child means to you. wow.
For me, it's the former where the child will bring me more/higher purpose to my life.
I am a father to a 1yr. I've never felt (never having a pet) unconditional love. My boy (currently ;-) does not care how much I have or make, what I look like or my personality outside of not mistreating him. In return, he gives me a look, a hug, and a kiss that is undeniable unconditional love. My wife's look, hug and kiss are "conditional." ;-)
Before going any further, let me preface with my thoughts about family; I've never experienced a family. I grew up in a broken one where I was physically abused and I ran away at 18. Before having my child in my 40's, I did not want to be a father incase I became what my father was.....resentful, hate filled, neglecting asswipe. Having grown up in that environment, I wanted to make a difference to children who may be in the same or worse situation. So I volunteered to became Big Brother to 3 fatherless boys in my 20's. I grew up...fast. Kids are special and found out just being there for them is good enough to make you Superman. That's all it took. No need to lecture or do psycho analysis to make the "better", but instead just being there was all they needed. PS> the 3 boys became my grooms men.
Does my child make me happier? yes and no. Happiness with a child is a weighted question. Does my child make me happy? yes. Does he make me happier? difficult to answer but I lean towards no.
I think the answers to your question will be weighted by: what age you had the child, where are you in your career, are you happy with yourself and your life, do you love your wife and extended family? Will your child be a trophy you craft or someone you mentor allowing them to grow based on your influences?
Am I happy right this minute? Well, it's 2am, I just got finished cleaning his playarea of dried up breast milk and food, cleaned all of his bottles and toys, prepared meals for him for next few days and to top all that off, he just woke up crying in the middle unexpectedly. No reason why. FYI I'm a fulltime dad.
Is the happiness so strong it can overcome the hardship of doing something that doesn't come with instructions? this very minute; no. Tomorrow morning when he wakes up cooing at you? yes.
Lastly.. omg. Can't wait for him to turn at least 5 if not 7ish for this first Disney World trip and start on the Star Wars series of films :) Having high expectations that he will like the same...I'm over the moon about my potential happiness. I can only hope but never force. He needs to lead the way to his happiness...not mine.