the young ones are often nippy and defensive, and what they have going for them is the potential to change.
most of the old ones are calm and docile and good with people, especially the ones that grew up as pets and that did have lots of human interaction. there are a few agressive adults and they are hard to tame, but they are rare.
the problem i see is that people like hatchlings because they like to see them grow, pet stores only sell hatchlings, but BPs have a high life expectancy of around 20 years. more people should take the older ones.