Being so close to the World's Biggest Bookstore (http://www.yelp.ca/biz/worlds-biggest-bookstore-toronto), which in terms of selection is going to be the store to beat in any case, it should be hard for any other bookstores in a block-or-two radius to compete. Being inside the Eaton Centre (http://www.yelp.ca/biz/toronto-eaton-centre-toronto) to get some mall traffic, the Indigo in the Eaton Centre does its best to provide good service and selection.
A two-storey affair on the upper level of the Eaton Centre, the book store provides a decent selection of books and accessories in a store layout that's fairly pleasing. A central staircase leading to the upper level curls its way through the store providing a fairly elegant focus. The stacks are well organized, and the staff are helpful as well. Traffic is probably the only problem with this particular venue. Because of the mall traffic, and the amount of people coming in and out purchasing books and the like, there tends to be a constant din and buzz in the store, making it not as enjoyable a setting to sit and read for a while. But given that this is in one of the most high traffic malls in the city, that may not be the intention anyway. There's other stores for that for sure.