A Matter of Personal Preference
Like with so many things in life, picking Dijon mustard over yellow mustard, or vice versa, is a matter of preference. The main differences are health-related, but these are in such small quantities that it may well prove negligible to make a decision between Dijon and yellow mustard due to health concerns. Yellow mustard has lower sodium content, but other than that, there is no further difference in terms of healthiness. The real difference comes down to taste preference, with Dijon being sharper and having a more tangy taste, while yellow mustard is milder.