Barbas is great.
Clavius Vile can keep his damn mask and axe.
I'm keeping the dog.
I don't know about that? Barbas seems to be a little bit more pushy then the other dogs IMO, he's gotten me killed on several occasions on 5 playthroughs by pushing me off my high vantage points, he even pushed me to my doom once, I was trying to sneak my way past a dragon to get higher ground and it was working too even with Barbas in tail but it was once I got to my destination that he decided it was time to try and snuggle so he pushed me off my hidey-ho and right on top of the dragon who destroyed me faster then I could react after the fall

I give dogs a 5-6 out of ten, they don't complain as much as most of the companions you can get.