i have just short of 6 years between my two
pros
DS was at school , so I had one on one time with DD, like I had had when I had DS
DS could fend for himslef a little and i could concentrate on DD
When i was heavily pregnant/just had DD, lots of people willing to take DS out for the day etc as he was almost 6 and therefore not as much trouble , as say if he had been a toddler.
DS could understand and get used to the idea of a sibling in plenty of time, and i could make a fuss of how grown up he was
Cons
DS not pleased at all at a sister. but nowt i could do about that
there was a period of time where it was impossible to do anything with the two of them.. she was too young for anything DS liked, such as cinema, bowling, soft play etc.. that was tough
DH out a lot at evenings and weekends and it was impossiblet o get DS to parties/activities, as would have meant waking DD up to take her out. luckily friends often steped in to collect DS
now they are almost 5 and almost 11 and they play really well together, or happy to do their own thing and ignore each other
there is a fair bit of fighting and DS is convinced i always take DDs side because she is a little girl
but the other day DD was sick and DS was so lovely and protective of her