I think it depends on the baby's temperament, too. For some reason I remember Munchkin being an absolute monster once those first 4 weeks (you know, when they sleep, wake up for a feed and go back to sleep?) were over... I'm sure she probably wasn't *that* bad, I was just overwhelmed by the adjustment to being a mum...
Squirtle though seems to be much more placid in nature, sure she can throw a tantrum just as good as her big sister but she's easier to settle, loses her temper far less frequently and just generally seems to be an 'easier' or 'better' baby than what Munchie was.

That being said, babies are great - it's the terrible twos that have me pulling my hair out right now!! I can't WAIT until this little stage is over!