I am a facilities manager, and I deal with over 300 restaurants across the country that need repairs including painting all the time. I have supervised more painting projects than I care to count. Low-voc paint is made from less toxic materials so in general it's better for the environment and those who live in it. You can definitely notice the lack of smell - there's no "fresh paint" smell and from what I've seen the quality seems comparable. I think it would be the better choice for a home with a toddler.
On the other hand, it is a lot more expensive and it's possible you may not be able to get the exact color you wanted. If you decide to go with traditional paint, go one room at a time and allow for plenty of fresh air to circulate through the room for several days. Another trick you can use is to mix vanilla extract into the paint, maybe a few teaspoons into a gallon. I have no idea why it works, but that cuts way down on the smell.