Pros
There are some really good people working there, there is no doubt about it. And you will surely learn something regardless of your skill level. Also the working conditions are quite good, especially for a Canadian company. Offices in Montreal are quite outdated - although it depends on which floor are you working. Also the variety of the opportunities is good.
Cons
Unfortunately, the management is too far from the reality. Upper management has definitely lost the it, they do not have a solid idea about the company's future. IT guys are the worst at Nuance, the work equipment is selected inappropriately and is not well managed. Also some of the business processes and some key people simply destroy any innovation and many good efforts and ideas just die. Lots of politics and "blanket pulling", more than I ever seen anywhere. Very questionable practices for bonus payments. Very silly travel policy for the employees. Lots and lots of redundancy at the technology and infrastructure level and it seems to be encouraged rather than discouraged. Some departments are like other worlds, with their own laws of physics. it is a strange place that you may first not understand, then like it at the beginning. But the longer you work there, the more dissatisfied you become with your job. Almost anyone I knew before Nuance who joined Nuance at some point have already left on their own.