We actually considered TTC from January, and my DS is the same age as yours, as you know LOL. Now I'm thinking I need more time, so we're looking at about a 2 yr age gap. My sister and I are 2.5 years apart, and have always been pretty close. All the same, I have a brother 10.5 yrs older too, and we're also close. I think whether or not kids get along can have a lot to do with their individual personalities moreso than their age differences.