My experience comes with fostering a CAG for a few weeks before he was transferred to my mother in laws house (they bonded very quickly)
The good: Toby is 26 now and I fostered him when he was around 20. I absolutely loved the sounds and mimics and words he would say. His words have increased over the years from being with my in laws. He makes the squeaky noises that dog toys too (as they have 2 chihuahuas), he mimics the microwave, he says "hello" when the phone rings and he also says these things : "rock & roll, come on!, want some apple?, wanna take a shower?, let's go outside, want some popcorn?, see you later" and so many other ones. He also farts (and he did this when my mother in law took him to the vet one time and the entire office was quiet so everyone heard it and thought it was her at first, lol). He's also content to sit on his cage or in his cage and observe everything around him, indoors and outdoors.
The bad: I'd have to say the floofies and the dander. It's all over everything. They have a really good air purifier and it helps, but it's still there. That's probably the worst thing for them as what I have to say regarding the ugly is my experience with him as we do not like each other, lol. He does fly off the cage (well kind of falls because he was clipped his entire life until my inlaws got him) and if your feet are on the floor, you better pick them up, ASAP or he will bite your toes and he doesn't nibble or nip, he bites and draws blood. (I guess that can be considered the ugly as well)
The ugly: He lunges. At me or my kids or anyone who isn't my inlaws. He doesn't fly, but if he makes his way to the floor and I'm at the house, I have to put my feet up or leave because he will come straight for me (birds can sense fear and he senses mine when I'm there.) If I go to feed him when they are on vacation, he will make his way to the perch beside his food and water bowl before I can get the bowls out and lunges. I do not see him much as I'm not over there often so I don't really have a chance to work with him. I do leave treats on the outside bowls when I'm there so that when he comes out he can get them, but I'm careful to never go near him. I have a scar on my ankle from him because I didn't put my feet up one day as I didn't realize he had gotten off of the cage when I was there and came hunting me.
Toby is a good bird for my inlaws and settled into their routine pretty easily. It took my father in law about 5 years to earn his trust to where he could pet Toby on the head without getting bit or leave treats/feed him without getting lunged at. He no longer puffs up his feathers when I am near his cage, but the lunging is still there and likely will always be. He will likely outlive my inlaws unless something happens to him (he does have liver issues) but I requested that he be sent back to the rescue instead of with me as I am honestly terrified of him, yet Macaws don't scare me in the slightest and I've been bitten way more times by them, go figure. It's not to be mean, I just know he would never be happy with us as we are both scared of each other but he can bite to show his fear and I can't do anything but stay away. I do love Toby but it just wouldn't work out with us. I do think we could've bonded when he first came to us had he not met my mother in law but it was love at first sight with her!