Why not just purchase a CD or Cassette tape with calls?
They’re good; we’re not knocking them. Anything legal that makes you a better hunter is positive, but most of these are recordings of game callers at some competition. They don’t usually name the call or isolate it so you can practice it. Cass Creek has instant playback. A player and speaker system would have to be purchased and are probably not shock or water resistant. Cass Creek game calls conveniently fits in your pocket and is lightweight. “Do I want to hunt, or do I want to lug and set up a cumbersome calling system?