Pros
I was able to work my way up from entry level and very little Linux knowledge to a management position in the most The Linux Administration department over three years--so I would say the biggest pro is the ability to grow there. They encourage you to learn, and promotion is attainable if you work for it, and are willing to meet management expectations. Also free food and stuff.
Cons
Its changing, not as drastically as some other reviews make it out to be, but its a publicly traded company now, so its just different than it use to be. There are some benefits to that, but there are also some draw backs. One drawback is the fact its slower (but still a real possibility) to be promoted. It use to be a smoother process, that much is for sure. Also, the general atmosphere is more corporate than is use to be, and policy has become frustratingly strict in some cases.