We have 2 Amazons - a yellow front Rio and blue front Bella. Here is my experience.
I have watched Bella peel my husband's skin from his thumb like his flesh was ice cream and her beak was the scoop. I am not exaggerating.
When they're excited, Amazons can deliver serious damage. Even if they're happy, they seem prone to over-excitement which can lead to biting. They are drama queens of the highest order. Add hormones to that and bad things can (and sometimes do) happen.
They're not bad birds, and as long as you know how to read them and they learn how to read you, they can be unbelievably sweet, fun, and funny. Rio is gentlest bird I have ever met and I am 100% guilty of letting her on my shoulder. She's also 26, so the worst of her hormones are behind her. The one and only time she has bitten me was in the middle of heavy hormones and a result of redirected aggression.
However, I cannot handle Bella with my hands or even safely treat her from my hands. She WILL bite me. There are times she will fly from across the room to attack me (usually if I have something in my hands - we have theories about the woman at her previous home :\ ) With months of patient work, I am able to have her step up on a Tperch for me. I can also have her fly to the Tperch upon request. Teaching her to get on the Tperch has allowed us to have her "step up" for others as well, and maintain some safety, as she seems prone to attacking women (again, theories). If nothing else, I would strongly encourage you to teach your guy to hang out on a Tperch. You never know when it could come in handy (if nothing else, it makes it much easier to get their weight on a regular basis). You could try doing a "stay" command so he learns this is a time when he needs to stay on the perch in order to earn a big treat.
Both our Amazons love music! Even though Bella doesn't much like me, she still loves when I sing to her. Whomever had Rio before us played a lot of Zelda, as she whistles the Lost Woods theme and will lose her mind with joy if you whistle it back to her.
I don't want to scare you away from your guy - just be aware that even the best, sweetest, gentlest birds are going to have bad days, and when they're hormonal, those bad days can be especially bad. Always remember that Amazons and other parrots are still wild animals, and they will never be 100% predictable, even with a strong bond and lots of love.