There is no RIGHT OR WRONG in regards to this at all. Its personal choice. Mine are all 20 months apart and I wouldnt have it any other way. My eldest is 6 then 4 then 3 and they are the greatest of friends. it wasnt hard, my eldest never missed out. i do think my middle daughter didnt get much in the way of 1 on 1 but she is a brilliant child who adores her sisters so nothing wrong there. As for coping. I think this time round is going to be HARD for me. When #4 is born my youngest will be about to turn 4. Which means school and kindy runs. UGHH. But I personally needed the break, for my body and sanity LOL.
But I plan on popping out #5 ASAP after #4 comes into the world. Probably around 12 - 18 months age gap. Then I am done lOL. I cannot have just this one more, I dont think it wil be fair on her to not have the closeness with a sibling like all her big sisters have (Gees why do I suspect YET ANOTHER GIRL??)
So personally I like CLOSE ages. I was 18 months younger than my brother and we grew up the closest of friends and still are. We shared all our adventures and it was fantastic. I want my children to have that. To have the ready made playmate at home. Besides I always planned on stopping once I hit the big 30 so times a ticking.

As for big age gaps. I can see the benefits but for me it wasnt suitable. I want to be home with my children in their early years. I dont use childcare. So having them close allows me to put aside a few years, have the masses of children I so desire without taking myself away from the work force for over 10 years. Mind you it probably will be 10 years but hey........... Atleast staying home with 3-4 kids is actually financially the better alternative LMAO.

Each to their own. Dont let anyone tell you when how or why.