It's the sucking action that is stressful. The more delicate the fish the more harm possibly to it.I am not sure how being sucked into a plastic tube is any more stressful than being chased by some one with a stick into a net. I'm thinking being trapped is being trapped no matter how it happens but if the experts say so I guess I'll believe.
I prefer the net and tickle stick method. I had a slurp gun when we lived in Key West and didn't care for it. Maybe I just didn't practice with it long enough. I was never in a hurry to catch the fish. If I didn't catch one one day then there was always tomorrow and the day after that. I didn't work when we lived there so I was in the water 3-4 days a week usually 5+ hours each time. I sure miss those good times. :bounce3:
Like others have said, be sure to check the regs and make sure you have what you need.