We have the pet hair Roomba and it's alright. It works for us because we have all wood or laminate floors, and picks up the dirt, pet hair and dust. However, we have to be proactive and clean the hair that wraps around the brush. It's kind of a pain in the a**. However, it's worth it to not have to ever sweep... lol. We try to run it several times/week when we leave for work, and we don't ever have to sweep (except for big messes like Christmas tree needles).
All of our pets completely ignore her, but I could see how it could be irritating if she bothered the animals. Roomba works for us, but she isn't for everyone. (Yes, she is a person to us
)