Bum, I'd started a post earlier and it's gone now.
Re: age gaps. After DS1 we were adamant we'd never have another. Pregnancy was awful (birth was actually fine!) and DS1 was an angry, high needs baby who's still a highly strung 5 year old (who had massive tantrums in front of the whole school yesterday). But, biology caught up with me and we eventually decided to have another.
We also couldn't have afforded two full-time childcare places (or for one of us to stop working, and part-time is financially ludicrous). Which confirmed the 5 year gap. And I have to say, this age gap (so far) is working brilliantly. DS1 can almost be trusted to watch DS2 for a few minutes while I'm in the shower, hanging washing etc. But I do still find myself saying "don't squash his head" etc as someone up thread does! He's old enough to understand the shift in attention, etc. too.
Ah, that was it. Sympathies for Time. I've mentioned that DS1 was is hard work. Some babies just are. It was some consolation for me that he was is also difficult for the childminder (who is a baby-whispering-goddess of childcare). So it really isn't us (apart from the genes that make him so... determined!). And to reassure me further, so far DS2 is a far more placid baby!
We are also done at two children. Though I'm enjoying DS2 so much I'd happily do it again and again! But realistically, two is plenty!