I used to have an older Roomba, but did not find it did well for pet hair. However, that was when they first came out many years ago and I am sure they have come along way! The new one that they recommend for pet hair with the auto-dump feature is the Roomba i7+. There are lots of videos on Youtube from users with dogs and hardwood floors. From what I have seen, it seems to be getting great reviews in that regards.
I personally love my older model Dyson. I have tried buying newer ones a few times but the older models seem to be made better. It works great with pet hair. Of course, it does not clean the floor by itself – unfortunately!