Pros
The benefits are pretty great, especially the healthcare packages. It's not a bad company to work for at all, especially if you're looking for a place to grow within journalism. If you're entry level, this role is a great starting point because you interact with so many different groups and you'll learn the basics of news operations, news gathering and some editorial through shadowing/observations.
Kontras
It's journalism so it's very competitive to get promoted. CNN doesn't necessarily backfill, so hiring from within isn't really a given. They actively recruit outside the organization, so when roles open up it's not like being an internal candidate is some kind of competitive advantage other than you being familiar with the company and it's business applications.