I don't have an Amazon, but my Grandma does. She got him when she lived in South America and brought him back to the States in the 1980s. He must be getting close to 40 years old now. I don't know how old you are, but that is something to consider, too, when deciding whether to get a baby or an older bird - they live a long time.
The good thing about Amazons is that they are very easy to "read." My grandma's Orange Winged Amazon reminds me a lot of my caique in that respect. He has very definite likes and dislikes. He's never really liked men. He likes kids. Adults, he may or may not like, other than my grandma. He bites really hard, but like I said, it's easy to see when you're about to get bit. He talks quite a bit and is pretty easy to understand.
Personally, I prefer getting babies to older birds, but I'm like that with all my animals - dogs, horses, birds. I feel like it's easier to develop a relationship and a good understanding of each other when you've raised them. I just haven't had good luck with older birds. My mom has my Sun Conure, because he loves her and hates me. I got him when he was older. I think he never forgave me for taking him away from his home. That's just my experience, though. I'm sure there are plenty of people out there who have had the opposite experience. Whatever you decide, I would spend as much time as possible with the bird before bringing it home and know that the bird may be different once you get it home.