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.