I am with Journeyman on this one. I almost exclusively flyfish for trout and barbless hooks are a mandate in a lot of places I fish. I can't remember the last time I used a barbed hook and if I buy a fly with it, I file it off.

I have a tool like the one you linked but I rarely use it. A hook without a barb backs out pretty easy. Like Journeyman, I don't ever recall losing a fish because of the lack of a barb.