Pros
The beneits package is really quite good, especially the 401K program. The employee bonus program is also pretty good, but I do feel like it's partly a way to not give larger pay raises, so it may be a wash for a lot of people all said and done. One of the other nice things is the amount of money they sink into training and education resources for consultants.
Cons
You can start o feel somewhat isolated when working at a client (especially if you're the only one from Sogeti at that client). Also, you are often expected to do things "after hours" and off the clock for Sogeti (i.e. conducting interviews, working proposals, company meetings) that go above and beyond billing 40 hours at a client. If you understand the revenue model and how to contribute to that you will generally be compensated well.