You recovered a clutch of owlbear eggs and may raise one of the hatchlings as a pet. If you possess a class feature that permits you to take a bear as an animal companion or mount that progresses as an animal companion, you may instead gain the service of an owlbear. The owlbear companion uses the stats of a bear companion with the following modifications: all Handle Animal checks made to train or handle the owlbear suffer a –4 penalty; the bonus granted by the devotion ability increases to +5; the creature’s starting Charisma score is 10; and the animal companion looks like an owlbear instead of a normal bear. This owlbear is considered an animal for all purposes.
So as I read it, you take a big hit to handling the animal for a +1 to some will saves and Charisma 10. On top of that, the bear companion doesn't really seem all that special (only gets up to medium, doesn't have grab or anything).
Do you think it's worth it overall? I mean, outside the fact that you get to have an owlbear best friend, which is pretty cool for flavor.