I have a couple of characters that started using the Keeper as a follower, and I noticed that she doesn't seem to ever get beat down. So my current one, a not really powerful hunter/archer at level 9 decided to shoot a giant with her fine long bow. I thought I'd see how tough the Keeper is, and she stood up to that giant and all he could dish. I love it when she says, "Oh ho, not so fast!" just like Jordis, same voice btw.
Diana the huntress just sat back and plunked that giant a few times while Keeper took him down with a Banded Iron Shield and an Iron Mace of Burning. Oh yeah, she never even had to take a potion.
The Keeper is definitely a keeper, but I don't know if I'll keep her for a serious hunter play through....