No real benefit. But a REAL pain to clean. Also makes gun MUCH louder.
Barrel porting is pretty much snake oil. Realistically, it might reduce recoil and muzzle jump by 2%, but many independent tests have proved that barrel porting is not near worth the cost. Talk to people who have paid to have their barrel ported, and many will say they can tell a difference. Unfortunately, I think it's all in their head. After paying $200 to have holes drilled in their barrel, most people don't have the %&!!$ to admit they can't tell a difference.