Overall, having the correct letter format will guarantee people that they can have the upper edge against other job applicants. All they need to do is to keep it clean and unique. There is no need to have a very extravagant cover letter. Just indicate all the essential things needed that can help them to get the job they need.
Of course, you will eventually realize that even if you do not get that frenzy over the cover letter format, you will still have to pick one template to start on among many choices. Thus, it pays to know some essential points that will help in making a good cover letter.