I know several people on this board have taken newborns with them, and many of them had very good trips. Since none of them have replied yet, I'll give my opinions.
I think that taking a baby would be infinitely easier than taking a 1 year old. The baby will sleep in its stroller when it's tired, and you don't have to worried about baby being scared on HM, PoC, etc.
The downside would be that you really don't want to travel with a too-young infant. I can't recall offhand what the minimum age is for flying, but it is several weeks after the baby is born. Also, you have to keep in mind that young babies (and even toddlers) can't regulate their body temps as well as you can. Personally, I wouldn't consider taking a child under 3 or 4 during the summer. It's just too hot. You can't even use sunscreen on babies until they're 6 months old, and you can't count on keeping the baby shaded continually so that there is no risk of sunburn.