Pros
CDW has a decent work from home policy, which is a plus. We get free lunches from vendors fairly often, and the location in Chicago is great, with easy access to mass transit. Overall, I find that the work hours are fine and there is quite a bit of flexibility, although that varies from team to team. Finally, it's a great job to make contacts, even outside of the IT industry, as we have a vast number of customers and vendors that we work in close contact with.
Cons
First and foremost, the pay and benefits. Pay varies wildly between departments and even between people in the same position. If you're in any kind of support role, you're getting paid at 50-100% below comparable jobs in the industry. The 401K plan is rock bottom matching and it takes forever to vest. The health plans are expensive, especially for a company that has 10 billion in revenue for about 7,000 employees. Even though the pay is low, the workload can be brutal. Lots of teams are completely understaffed, and backfills for positions can take months so CDW can cut costs. Decent IT support could make up for some of this by increasing efficiency, but CDW's IT department is poorly run and ineffective. The pay issue might be a symptom of management's complete lack of understanding what goes on at the ground level during day-to-day operations. Decisions about how to best manage business processes seem completely arbitrary or based upon erroneous information. Thus, for career enhancement, you're better off focusing on cultivating the positive attention of people in upper management than on doing your job competently or displaying initiative, as no one above your direct manager will notice the latter.