There are 7 1/2 years between my 2 boys. There have been pros but mainly cons.
Pros- The eldest would have been awful to a new baby if he had been much younger ie 2/3, as he was to his cousin.
Cons- There is such a gap they are at different stages totally. The eldest misses out on such things as bowling, movies, meals out, as 3yr old is such a handful as well as being "an absconder."
When the eldest is doing his prep, the little fella is always grabbing his books, pens etc and running off. He also hates the attention taken away from him.
The youngster will not allow his poor older brother a lie in! So late nights for the 10yr old are still followed by early mornings!
I had 'got my life back' and had it taken away again, so it has been very,very hard for me physically and emotionally.
There is only 16months between me and my sister and we are very close. We went through all stages together and are best buddies. My Mum found it much easier after I had come out of the baby stage, as we were playmates, so she didn't constantly have to entertain just one of us.
So my opinion is - the closer the better!!!