I am current FY at Darden. Long term, I believe Darden has a considerable advantage in terms of the breadth of the alumni network and reputation as a solid T15.
In the short term, please make sure your career goals are aligned with what the school is able to offer you. If you are 100% sure you want to go into Brand Marketing, McDonough will get you there and Darden will not provide you with a significant advantage. But if you are even slightly considering consulting, banking, or leadership development programs, then come to Darden.
For consulting, MBB recruits in very few numbers outside of T15. I know Darden places around 45 people in MBB each year (approx.15% of the class). Banking is excellent at Darden as well-almost everyone who recruited for IB had offers. Darden has many companies such as 3M, Danaher, Davita, Mastercard, etc., that recruit for their flagship LDP, providing the recruits fast track promotion to senior management. All these opportunities will be difficult to come by at McDonough. However, if you are looking at marketing at CPG (P&G, Unilever etc.,), Retail, and to some extent Tech, McDonough will provide with similar exposure to Darden as these companies tend to recruit at programs below T15 as well.
Hope this was useful!