Pros
I have worked at FedSolutions 4.5 years and have had outstanding growth in my career and worked (overall/the vast majority) with fair and kind people. Work closely on all types of networks, clients, personalities. A team first / client first culture (Hasmik particularly will go out of her way to help any employee or client). SMB issues and challenges, but employees are reasonable - so we all try to help out each other and clients. Outstanding part of DC (places to eat, after work items).
Cons
No sink in kitchen (this is being added in 2016 though), parking in this park of DC is brutal - also the roads are tough to navigate because of traffic (many staff use metro because of this). Employees must be able to wear many hats at times (handle different roles), this is part of the start up world, not just FS.