First time I've done his associated quest and i must say he's extremely annoying (not the talking, that's actually quite funny at times). I've also never had a dog as a follower. Granted, he comes in handy insofar you're able to go anywhere, at any level without much fear of dying, but [censored] me, he's a Royal pain up the backside. Always pushes me as I'm about to fire off a shot with a bow, when i'm talking to people and so on.
Dog's barking gets annoying, But that means you just stay away from them when they follow you, Get a couple steps ahead.
Barbas is the most annoying dog, But since he is the Merchant Mudcrab from Morrowind. I could Forgive him.
Meeko is one of my Favorite Dogs though.