Tallulah loves her yak chew. Petunia prefers the bully stick.
The yak chew on the left is unchewed. The one on the right is after Tallulah chewed on it since Wednesday. She's still chewing on it, but mom will take it away before she swallows it. Or after, depending on how ornery Tallulah might be.
So our vote is that the yak chew is much longer lasting for aggressive chewers like Tallulah. We do think that She's darn near OCD about chewing on her stuff. Remember that she wore the pigment off her lips going after a saddle bone.
You will need to watch your doggy with this one though, especially if they are prone to swallow stuff. The chew is really hard and probably won't digest very quickly in the stomach. It could cause an abdominal obstruction if too large.