Do you think automatic functions like word correction, grammar correction or word prediction are useful? What are their good and bad characteristics?

Yes, it is useful and I think that the positive characteristics of the automatic functions such as word correction, correction grammar or prediction the word: It is to win more time,and  making the concept of text and sound vocabulary and language, so make it easier for the reader to read

As for the disadvantages of these functions can be overcome by disable these functions