I would most certainly recommend The Westin NMA. It has a far more central location and since you are in tourist mode I think that there is no better location. It is on the 900 block, one block from John Hancock and only 2-3 blocks from the best shopping in the Mid-West. Lakeshore and City Center are a good deal further down and much more secluded. The Westin NMA was also recently remodeled (with 5 years) and the rooms are very nice. The rooms are of great size, and if you are SPG Gold or better you will be able to upgrade fairly easily on those dates I would think.
Hope this helps! And you should eat at Bistro 110 on Pearson St just 500 feet from the hotel. Also look into Second City, it is a comedy club (tasteful) that is in the theatre district. (
www.secondcity.com)
Hope that helped!