In answering this question you have to consider the strengths and weaknesses of both candidates. It seems evident, particularly after watching Reese against Stanford, that he has a better feel for the offense and that he is the better option. Golson is without a doubt more physically gifted. He has a nice arm and he is very fleet-footed. However, it was noticeable a few times that Golson took a few sacks that Reese probably wouldn't have taken because he was standing in the pocket and holding the ball for too long. Therefore, Golson's speed and escape-ability may not be as advantageous as you might think.
Another aspect to this debate that was hard to ignore against Stanford, an aspect that was aptly pointed out by ND’s color commentator Mike Mayock, was that Reese may have a better knowledge of his teammate’s strengths and weaknesses. Time after time, Notre Dame put together nice drives only to come away with little or no points. Tyler Eifert, arguably the Irish’s best player, was single teamed on many occasions and Mayock rightly pointed out that you need to take advantage of that situation, particularly in College football and when you are having a hard time scoring points. After Golson’s unfortunate injury, Reese entered the game and exploited those single-team matchups. Reese also audibled out of plays when Eifert was double-teamed after noticing that Stanford had fewer players in the box than on previous plays.
These instances are just some examples of what Reese would bring to table. It seems that Coach Kelly may be better served to let Reese take the reins for awhile and let Golson, who is just a sophomore, learn the offense and get better in game situations. At this point, Reese is the better option to start and maybe Golson could benefit from an occasional series to switch things up a bit.