Well socialized babies tend to be more secure in themselves and their environment, curious about their surroundings, and more adaptive to changes. They appear to look upon humans as good guys and tend to be more cooperative and affectionate.
Birds are very intelligent creatures.
Also like human children, an upbringing of low attention, fear or rough or insensitive handling can result in problems that the new owner will have to contend with and fix later on. It will not be too late. Other people like larger birds, or like the way the Vos looks or the Red Side, or Grand or whichever. Get what YOU want. If you are concerned about problems with one bird intimidating the other because of size, one can never really tell just as with people.