I personally think it dEpends on situation.

Bird vs bird I believe demonic bird would win due to the extra range with xbow over Sang LB.

Bird vs bear I believe sang LB would win due to its higher nuking capability. Xbow just doesn't have enough "punch" as a LB.

Birds vs Mage can be either or. Mages at 61 are normally very op. if you kite, I'd use Demonic. If you would rather nuke, I'd use sang LB.

Although sang packs more punch than demonic, I feel demonic is better vs birds due to range. And either way, you will die in bird vs bird and you use a shatter blast combo and both hit; regardless of demonic or sang.