My DD is 4.5, so there'll be a 5 year age gap by the time baby arrives. My pregnancy with her was pretty ok, but, like this time, I was very tired and grumpy and I definitely lost focus on anything else!
She wasn't a particularly easy baby in that she refused a bottle, hated prams and ended up co-sleeping from about 8 months. But she is an absolute dream child - has her moments but is so well behaved, I can take her anywhere and she's really polite and sweet! She spends most of her time writing little notes and drawing pictures..
My sisters (especially the ones with boys!) have really enjoyed teasing me that I can't be that lucky twice!