Pros
There is an atmosphere of freedom, everyone can work on their personal efficiency and develop their skills. The teams are friendly, management is rather open and ready to help (very busy though). Employers' motivation is definitely taken into account so if you don't like something just talk to your boss (even if you don't like your boss) and explain. They will try to help or they will explain if they cannot. Be consistent and patient and help the management with your reminders and suggestions, they will appreciate. Schedules are totally flexible. Good opportunity for middle-level managers - always needed, have total freedom of methodology, team management approach and etc.
Cons
The salaries are not super high. I never been a good negotiator but I saw other good people leaving the company because of the salaries. Again, management is very busy so it might take a while before they answer your requests. The company hire to many juniors which results in quality cut-offs sometimes. The company work with Russian clients, which brings the downsides: - projects might be demotivating when people realize that some guy in Moscow gets even more money that the company itself just for arranging the deal - many state-managed organizations are full of incompetent morons who cannot stick to last week decisions even if you put everything written on paper