I think it depends on what your plans are. If you just want a pet, or know you have a few years before thinking of breeding them, I would get a baby. They are way cheaper and it's fun to watch them grow and their color develop. I also think if you raise them from babies, it's more rewarding when they produce a clutch for you.

On the other hand, if you find a good deal on an adult, and it would fit into your plans perfectly, I would definitely buy the adult. Adults also tend to be more docile, so in my opinion, I don't think the "raise them from babies so they bond with you" is really relevant. I have found that some baby BPs I have purchased were sweethearts and some are temperamental, but the adults I have purchased were all very docile after giving them a few weeks to settle into their new home. In the end, they all have their own personalities.