IME: I will either get a repeat of something already written (this happens all the time with java getter/setter boilerplate if the class isn't the one I'm currently working in), or I get some junior level attempt at what I ask it to do. The second case is the best case, and it still requires a code review with a fine toothed comb. For example, it loves to suggest plausible looking but non-existant methods on popular libraries.

It's one of those things where a language aware autocomplete will often save me more time, because it doesn't try and second guess me.