Pros: stock purchase plan, employee deals on everything, overall company vision and direction
Cons: large company means lots managers, directors, senior directors, vp's, snr vp's, evp's, etc...
It's a huge company so right off the bat you need to be cool with that. It's very unlikely you'll be able to see your contributions in the company numbers at the end of the day.
They own just about everything worth owning in Toronto these days in terms of media, sports, content, etc and employees get great deals on them.