Pros
Great place to socialse, work with blue chip clients and the world biggest brands. This workplace has no places for errors and would teach you work discipline, and how to work well under-pressure and be advocate. You got to go to a lot of fancy places in Soho, and work with som leading media suppliers (GG, FB etc). It is a perfect place for graduates and if you appreciate a highly sociable workplace. It is said there is company politics, however I have not seen this within my team. You’ll get nice perks from clients, plus the offices are nice, got great cafeteria / free breakfast and basic food if you work later than expected.
Cons
IT infrastructure is not world-class
Slow moving and reluctant to change, serious lack of innovation
Salaries are low, within industry benchmarks lets not go compare it with in-house pay…
Long hours due shortage of staff and inefficiencies of technology
Billing system is ridiculous - you're gonna spend a good amount of your time administering POs dating back some times years
You'll be a small clog in a big machine
Slow career progress
Too much responsibility and workload given to junior staff
Learning is limited to “specialist industry best practices” - you won’t really get to see the wider picture of the media mix in a different context
Enslaved to the client - literally