Pros
The team I worked with was amazing. Every single person was talented and skilled at their area of expertise, and together we managed to do great things under a large amount of pressure. They had a very personal approach to interviewing and the job in general. Lots of lunch outings together as a team, that kind of thing. The benefits they offered me were better than what I had previously.
Cons
As mentioned in the title, there's 0 job security. Shortly after I joined the team it became clear Dell was selling Quest, and no one had indicated or disclosed that during the interview process. There was a lot of unknown up in the air, and a lot of people looking for other positions due to the uncertainty. There have been multiple rounds of layoffs, and direct management has no say in who gets laid off. As someone else mentioned, you can be absolutely killing it at your position and still be laid off. Full disclosure, I was recently laid off. My boss told me he had no say in the matter and was surprised I was on the list, that was given to him, not decided by him.