I have 2 years between each of my 3. I was certain I didn't want a larger gap, and was fortunate it worked out. (I was set on a 4th with the same gap but my marriage ended)
For me, it felt like a natural continuation. I started trying to get pregnant soon after stopping b/fing & got pregnant easily, within 2 months each time.
I toilet trained the older DC at 2, just as the new baby came; so I only dealt with one set of nappies at a time. Again, I was lucky - they took to it easily & there was no great stress. I know other children are older - which is also fine.
I never had a double buggy. This was fine for DC1 who was a great walker and used the buggy board; less so for DC2 who was much smaller & got more tired. I had a lot of using a buggy for him while newborn baby was in a sling. Pretty exhausting.
The age gap was always fine; the increase in numbers of children, especially to 3, was really hard, especially with a feckless abusive H who left shortly after.
My younger two (boys) are v close, and do everything together eg the same sports, play together & so on. I think with approx a 2 year age gap you get this, less so when they are older. (But again, it's entirely luck they may also have different personalities).
Even tho things were v hard when they were little, I loved being with 3 small people, it was a happy time in spite of all the other shit I had in my life.