Pros
Qualcomm has a number of people who are exceptionally skilled and a pleasure to work with. The benefits package has been exceptional, although it has recently eroded slightly. If you are an engineer, the pay is good and the work is frequently interesting. You also will have excellent opportunities for advancement and career growth. Rewards for technical innovation are high, and typically commensurate with the impact on the organization.
Cons
If you are not an engineer, the pay is mediocre to poor and the work is rarely interesting. There are almost no opportunities for advancement, as almost all managerial positions are held by former engineers. Having all of the managers as engineers has led to a manage-by-the-numbers mentality across the board. An excessive amount of time is spent making the reports "look right." This also means that HR sends an endless stream of messages about "work-life" balance, while the managers ask how many hours will be worked this weekend. This, and the fear-based messages about the bad economy are annoying, but pretty typical in most large technical organizations. Many of the fringe benefits of working for Qualcomm are lost if you are not located in San Diego. Facilities in other locations are nowhere close to being as nice. For an example, in San Diego, almost everyone has an office. In another location, many non-engineers are sharing cubicles, and only upper middle management and above have offices.