1) Understaffed - People were constantly busy, and this isn't necessarily a bad thing, but in the case of CBS, it was a crap ton of work. I mean it wasn't just me either, people on every team were flustered and overwhelmed, it was insane. I think I was doing the work of 3 people at one point and the days were long. During the height, 10 hour days were the norm and I was constantly exhausted. Sadly, a lot of people do burn out and leave because of this. I'm relatively young in my career, so I don't think this is a terrible thing when you're starting out, but for someone later in their career, this can be a huge negative.
2) Management and politics - There's going to be politics everywhere and CBS has a lot of it. People are very keen on looking for someone to blame whenever things go wrong. At the same time, certain managers were placed in positions they shouldn't have been in in the first place and are extremely incompetent. This leads to unnecessary work and heated arguments between staff and even others in management. Unfortunately, CBS has a very "patient" policy and it's almost impossible for people to be let go. As a result, you tend to get some people stuck in roles they shouldn't be in and there's nothing anyone can do about it.
3) Knowledge Ceiling - CBS is a great place to start your career, but if you truly want to grow and expand your knowledge, you may need to go somewhere else after a while. This was the case for me. I learned a lot, but the opportunities to grow were no longer there. And I'm not talking about money or job title per se. Those things will come if that's what you're looking for. I'm talking about actual learning and acquiring skills. At a certain point, my learning consisted of self-teaching on the Internet and asking other people in the company how they did things. This is when you know it's time to move on.
4) Benefits - Only 8 sick days. Only 2 weeks vacation. No floaters. But at least you got the week of Christmas Day to New Years off. Although, depending on your team, you may actually have to WFH during that time...