Dale, I agree with you that it is as simple as you describe it when you start the process with an assambled saw (except that you should hold the tip of the bar up when adjusting tension, and retightening the nuts), but that was not really what was discussed here.
The downside of Stihls "bolt and collar" or "stepped bar bolt" system show up when the cutting attachment has been removed from the saw for maintenence (or whatever reason), or if the bar nuts has been loosened past a certain point.....