Pros
The people...co-workers are great. You see a side of the general public you never would believe exists. Sometimes work-life balance works for you...but it depends on what you mean by balance.
Cons
Nielsen was sold several times while I worked for the company. I loved my job. With each buyout Nielsen changed from the company that I loved to this place that cut and cut and cut, laying more and more responsibility on the employees that remained. It hasn't stopped. The reps and office people that work for the company love their jobs but there's no job security. You're always in fear of losing your job. Cuts have happen days before Christmas.... Just an overall lack of respect for the job the employee does. It's sad. You're subject to magical thinking... "It's your fault if the HH doesn't perform. HH sick, someone's past away? That's okay...they'll still wanna let you in to fix our equipment!"