There's a time and place to leave the barbs on your hooks when fly fishing. Most salt water species almost require that you have a barb, bass fishing would be tough without it, and some larger freshwater bruisers also need the added advantage of a barb. When you're trout fishing though - I would say, 99% of the time there is no need for a barb. Not only does it do far more damage to the fish, it can cause you much pain and suffering if you accidentally hook yourself. I personally double check anyone on my boat that's swinging flies around my face and make sure there are no barbs on any hooks.