Pros
There's a reason why Qualcomm is often listed in Best Places to Work surveys. Management makes sure to listen to employee concerns, needs, and wants, in order to improve working conditions as well as work-life balance. At times, they are even proactive about introducing new ideas to make working at Qualcomm better. Not only that, working at Qualcomm gave me the opportunity to work with and learn from very smart and experienced people in the field of wireless communications. Since many of these people are the pioneers in the field, I was able to get a sneak peek at upcoming technologies--and everybody was open and willing to share with me. People (even some quite senior members) are generally happy to chat, no matter how busy they are.
Cons
Since it's a large company, sometimes it seems that an individual's contribution does not impact the company much. The managers do try, however, to recognize the contributions, even if it doesn't eventually pan out.