My DH is the youngest of six children. There is five years between him and the second youngest: They have always been pretty close. There is either three or four years between the rest of them.

As someone with kids only 22mths apart, I cann't help but think a larger gap would be easier (ie, not changing two kids with nappies, etc). The older one is at an age where they can enterain themselves while you are busy, they can be good little helpers (fetching wipes and nappies etc), and old enough to really understand and get involved and excited about a new edition to the family. Although there is only 22mths between each of my kids, there is 4yrs between my eldest and my youngest and it has been a great experience. She really is a Helper, and they still play together and get along fabulously.