They can thermally detect any living thing around you giving a strong pvp advantage. Like a night vision with wings. Plus they can put you and your allies in stasis and heal you whilst being an ice cube. Decent airborne mount -
They dont have the ability to pick up dinos, but, they can go extremely fast, especially when inprinted when swooping. If you want a fast flyer with a decent amount of weight and fairly high stamina, this is the one you've been looking for.
The Snow Owl’s healing ability is really good for farming blood packs. Just use the syringe as much as you can, then jump on the owl and heal. Bring a lot of food as the healing drains your hunger a lot.