I'd just make sure that the right methods are called:

```ruby
@user.should_receive(:save_with_captcha).and_return(false)
```

and

```ruby
@user.should_receive(:save).and_return(true)
```

Both are external dependencies and we assume they work correctly, we really just want to be sure that the right methods are called depending on the setting in case that gets more complex in the future.