I have just had No 4. I have had 4 in 6 1/2 years. My eldest 2 are 16 months apart so it has actually worked quite well in that I have 2 at school this year so it helps to ease things a bit.

Like Trillian said I think you are jusy busy when you have kids, I found going from 2 to 3 challenging but that was because I was doing kinder runs and live 50km from town so it made for long days with a baby.

My biggest gripe with 4 children at present is all the baby seats and boosters in the car. But given your eldest 2 are a bit older it hopefully wouldn't be as frustrating.

I was a bit like you I really really wanted 4 kids, Dh not so keen, took about 6 months of heavy discussions before he came around to the idea, and I love my 4 boys and can't imagine life without them. People ask if I'm going for a 5th (just for the girl) but I happily say that I only ever wanted 4 children and have no desire to go back again.

I think you should go for it too.