Hi bcma. Welcome to the forum. Glad you found us here. The Fox 40 (and CMG) are also widely used here in the United States. I use it and everyone I know uses it. Some people have started using a whistle called "The Dolphin", but I've never used it.
Don't mind Rutledge. He's just a little cranky today. 🙂 He's right, tho, that it doesn't matter which is the "best", as long as it works well for you and your superiors like it. Please keep coming back and asking questions.