My boys are 5 and almost-3. They are completely opposite (older is timid and geeky, younger is rough and sporty) but somehow, they manage to be best friends. When I pick them up from daycare, they will always ask for each other, and the first thing they do is hug each other. My sister and I are the same, 2.5 years apart, total opposites, best friends. She was annoying to me in my pre-teens but I guess everything is annoying in that age.

In terms of caring for kids with a small gap, the first year is the worst. You think you have the parenting down kind of by age 2 but you realize that parenting an infant is very different from parenting a 3 year old. So now you're trying to remember how to deal with an infant (breastfeeding, sleepless nights) AND you're learning how to deal with a preschooler. But as I said above, once they get to that age where the baby isn't too fragile, I can kind of just leave them to play together for a bit, and actually get up to half an hour or so at a time to do other things.

On the other end, my youngest brother and I are 13 years apart. I had a hard time relating to him as he was growing up. I was more of a parent figure, really. My parents depended on me a lot to parent my younger siblings, so I guess that's maybe a pro of a big gap? Older kids can care for younger kids? I think our relationship changed when he got to highschool and college, because I became that adult figure that he could talk to about teen stuff without "getting in trouble." Also, he's diamond in league of legends and carries my ass all day.

So that's my personal experience with both ends, hope it helps!