For some quick advice on this, think of the question not as 'Why Ross' but rather 'Why Ross
and not another school?' - so you need to mention things that are not only important to you personally but that are also unique to Ross.
Things like MAP and the hands-on nature of the curriculum are a great start. The alumni network for me always stood out as very connected, every interaction I had with Ross folks was memorable and interesting - but also the fact that you can have the best of both worlds, a smaller class size at Ross with one of the largest university level alumni networks with UofM.