I have got a training collar and my advice would be that they can be useful for specific problems such as the one that you seem to have ( sprigers are renowned for buggering off!!!), but they are a worthwhile purchase because as with all dogs you may find in the future that your dog develops a problem that the collar is useful for. Make sure that you have a dummy collar that the dog wears all the time so that the dog does not come to associate wearing the collar with good behaviour but returns to bad habits with its removal.
HAVE FUN!!!!!