Blue crowns are "Blue Clowns". A lot of fun. Fairly intelligent. They can do some nasally talking.
I have two of them. One I've had for over 15 years and I've known her when she was with my brother for 8 or 9 before that. The other is a rescue that I've had for close to 3 years now.
My old one, Tootsie, is a very noisy bird. Very over reactive to things like touching a blood feather. Screams if I leave the room and as a result she gets the bunch all stirred up. There is a possibility that she was a wild caught bird. She had a split band on her leg and I traced it to a Miami import station. However, she is very sweet. Loves to just sit on me and preen my skin though sometimes she finds a bump or something with her tongue then she drives the point of her beak into it which can get uncomfortable. Since I brought the other blue crown in, she spends more time with him but still flies over to me a couple of times a day for some scritching or to try to get me to give her some of my food. She is very food motivated and knows the sound of every container opening that could have a treat for her to eat. The biggest problem with her is that she just won't shut up. I think she has to relieve internal pressure with a squawk at least every 5 seconds or she might pop!
Now Rosco is an interesting one. He is still opening up after his experience as a rescue. I have no history on him at all. He is wary of hands though I can get him to step up, usually after he flies to the other side of the room then comes back. I think he wants to show me that he can go away if he wants. It is almost always one trip over, land on the playpen, look at me for a bit then he returns and steps right up. He is very curious and interested in everything that is going on in my place. If I go into the kitchen, he flies right over to his cage where he can watch what I'm doing. If the Senegal jumps onto the floor or is playing with something, Rosco lands somewhere nearby to watch. He also likes to land on my laptop lid and often starts talking nonsense to me. He is not nearly as vocal as Tootsie is and I think that 70% of his noise is just him reacting to her sounding off. He can be a bit of a brat, though. He often agitates Tootsie seeming just to set her off. They could be mutually preening when suddenly he will yank one of her feathers or peck at her or nip a leg. Seems to do it just to irritate her.
Overall, I think that blue crowns are great birds. They can be noisy, but what conure isn't? And the clever intelligence they have is fantastic.
Look for some posts by ruffledfeathers about the antics of Gilbert. As funny as my birds are, he seems to have even more personality. And there are some great photos of his adventures outside.