I've had a really good quality whistle for almost a year. And before that I had a few plastic ones to learn on.
But it isn't until recently that I've buckled down to learn it. I've been able to do everything but a stop. There is a tail on it that is tricky and it took a while. Finally I think I mostly have it.
So this winter the dogs will learn it. I've been told that even just the stop whistle is going to make a huge difference. You can be more precise about what you want, the dog responds better, etc etc.
I am excited because already in the wind on a big outrun I have had some trouble with the dogs not hearing me. So the whistle is definitely needed.
It is hard to Learn though. I am not musically inclined at all an have no ear for tones and such. But like I said I had a breakthrough so feeling like I almost have it. :)
Practicing at work was enjoyable for me, exciting for the dogs. And annoying for my coworkers. :)