Pros
Oslo Solutions has lots of direct clients across USA. With major supporting client in Seattle/Redmond, WA - Microsoft. They deal with big teams and groups at Microsoft. Candidates are screened with Senior Engineers who are professional and technically very strong towards technology side.
If you are a .Net and looking for a job at Microsoft then i highly recommend Oslo Solutions. The turn over time is very less, and Oslo is significantly growing from past couple of years.
Cons
Must report to multiple supervisors