As Ray ray says , i think its more to do with personalities than age gaps.

I do completley understand where you are coming from though, as i have a 6 yr gap between mine.
Why?
Because like you, i wanted to study, and when I weighed it up I figured it would be easier to manage study and family life with one child rather than 2.

I wanted my kids close together too, but I also didnt want to wait 10 -15 years for my babies to be old enough for me to study. It was brilliant doing my degree (in my 30s too), and a challenge, but im so glad i have done it.
My kids adore each other, but I still feel bad that my eldest was an only for 6 years and even now gets lonely, as the youngest is too young to join in the games he wants to do etc. As tough as that side of it is I am so pleased to have done the study, it was so good to be learning new stuff and mixing with other people outside of my usual circle.
As good as it has been to do that study though, the downside is that with the age/clock ticking thing, I had another baby straight after graduating, and now have to wait a few more years until I can get working and using my qualification.

I made sure I had the support set up in place to be able to do it, but even with that same support I dont think I could have coped doing it with 2 kids. I still was not able to do as much in some study as I wanted, cause I had to go pick up at daycare etc rather than going to the library for research etc.


All the best with making your decision.