They may want their dog to lie down at 200 yards away because a deer is running by, or come back to them in that instance. It is no different than you or I wanting our dogs to lie down at a distance because a cat, or a dog, or a mailman is passing. The only difference being that if he doesn't, we can reinforce immediately. The dog at least gets another repetition in that he must comply immediately, it could cost him his life. If it made a hunting dog too scared to do it's task, or diminish it in any way, hunters and field trial people certainly would not be using them on a daily basis, and having them as an integral part of their training program.
Field trials are definetly among the most difficult of all dog sports.
It demands desire, and precision at great distances, and in 'non-patterned' formats that make it all the more difficult. Our Las Vegas K-9 unit recently went to electronic collars about 2 years ago. Recalls, become quicker, smoother and very happily performed because the dog knows exactly what is expected. I would definetly recommend that you attend an electronic collar seminar and make up your mind for yourself.