Pros
If you are an individual with a security clearance, the SAIC "brand" has cachet in the government contracting arena, for whatever that is worth. With 44,000 employees worldwide, there are a lot of opportunities; the problem is finding them when you want them. Healthcare and other benefits are good. HR is responsive. If you are transitioning to SAIC from the military, you will be shocked at its efficiency. Their base salary was fair compared to BAE, and better than my peers at BAH. It is possible to get a signing bonus; I got a 5K one. Finally, SAIC also is involved in some great work, if you can link up with the right business unit.
Cons
Despite its reorganization, SAIC is still a company of multiple fiefdoms. Managers are concerned about their own bottom line, Business units and divisions are often indistinguishable in terms of mission and market segment. If your local management is good, things are great, if they are not, you will experience friction. Many individuals (including myself) conducted SETA work (glorified out sourcing) at the government client site. This gave us great exposure to the client, but none to our own leadership. As a result promotions, professional development, corporate goals and career progression were all big mysteries. For many people, loyalty waned as a result. This cycle feeds SAIC's high turnover.