I also think there's no "right" answer to this question and it's a matter of personal preference.
Our experience? We have 23 months between our two - DS has arrived smack bang in time for the worst of DD's "terrible two" phase. So it hasn't been easy. In fact some days have been downright horrible.
But after nearly 4 months we're starting to find our groove and things are improving and getting much easier (thank goodness).
There is the same age gap between my brother and myself and we are really close so I'm hoping for the same for my two as well - DD is really besotted with her little brother and that part is just lovely to watch