I'm not too sure barbed or barbless has that great an impact on the fish, although going barbless certainly doesn't hurt.

I seem to recall in my studies that using bait and the type of hook used (single or trebble) is more of a concern then the barb.

Also, how one plays, lands, handles, and releases the fish plays a very important role in determining if the fish survives or not.

Worse Case Scenario: You hook a large nate on a bait diver. The fish swallowed your barbless hooks while chomping on the biat. After a 35 minute fight (hey, it's a 20+ lb. nate and you were using 10lb line), the fish is netted and brought in to the boat. After a 5 minute struggle to contain the fish, the hooks are removed from the fishes tongue and throat. After the mandatory Grip 'N Grin (even I am guilty of taking pictures!), the fish is tailed back in to the water. But, since you're in a boat and the current is too fast, you can't hold on to the fish and it slips away to the depths of the river.

Yeah, you used barbless hooks, but that fish is all but dead.

Parker