I have 3 and we are WTT for #4
I found it quite easy going from 2-3. Poppy just slotted in really.
It's a bit daunting when you bring the baby home and you've got to get back into the swing of the whole newborn thing again whilst running around after 2 toddlers, and it didn't help my PP bleeding in the slightest but you just do it. Luckily I had a good pregnancy and easy water birth, the hardest part was being 9 months pregnant running after 2 toddlers while hubby was at work.
Honestly it's totally worth it, I'm an impatient, hot-headed lunatic and I manage fine
so much so that we're going for #4!