There was never any question that I would find out. My DH wasn't sure he wanted to know but basically if I knew, he'd know as I'm terrible at keeping secrets!!
It's not really a case of having more reasons to find out vs not find out. I always knew I'd find out when the time came, I think it's a very personal choice.
That being said I can tell you the reasons I'm happy with my decision
First obviously is the fact that I can call the baby 'him' instead of 'it'.
I hate not knowing whats going on. I like knowing I'm having a son & am able to prepare myself for that.
Like Penkee said DH & I are bonding with our son. NOT that you can't bond if the sex is a surprise. Just in our case we talk about what kind of things we'll do with him, what we want for him in life & what kind of boy/man he might become etc. Again I know everyone does this but we really like the fact that it's 'boy focused' for us.
I'm enjoying shopping for him while we have 2 incomes & I have the time. I love picking out little boy outfits for him & I don't want to have to rely on gifts.
My family is crafty & want to make things for the baby, easier if they also know the sex.
I think that's basically it. I do have to say that I HATE justifying myself to other people when they ask if I know what I'm having. Because they always say "Oh you're ruining the surprise". I always tell them that I'm still having a baby & everything everyday will be a surprise to us.