He isn't barky. His few barks have all been issued as an invitation to play, coupled with a play bow. He has been taught nothing, but is tickled with praise. I have found this to be an unusual combination.
Though he was described as not house-trained by the person who rescued him, he has been clean in the house 72 hours, with frequent visits outside and the judicious use of a crate. He was also described as 'humpy', but the neuter seems to have put a stop to that - that, and neither my dog or cat would stand for such foolishness.
He hauls around soft toys half again his size, and pounces on them with great ferocity.
He did bite the crap out of me the first night he was here when I tried to put a sweater on him. It was a completely uninhibited bite - I bled - but I tend to give him a pass on that one because he had just been neutered a few hours before, was in a strange place, and had recently been abandoned in a dog park and "roughed it" for several days. I think my ham-handed effort to put his sweater on caused me to hurt him accidentally. I handled him as little as possible for the following 12 hours, and since then he has been very affectionate and tolerant. I have been handling him all over and cooing to him, for the last 24 hours, so he's evidently decided I am not vicious, merely stupid and clumsy.
He is energetic, not afraid of strangers, good with dogs and cats. In short, he is a winning creature that I might think of keeping, but for budgetary considerations. And, well, he's a Chihuahua...