Pros
Music on in the office (same songs everyday) dress down environment, water on tap and it's in central London so good transport links. Also great if you love hearing Z list celebs name dropped into conversations.
Cons
Most of the Directors are unpleasant and untrustworthy, often whispering to each other and you can hear them saying nasty and personal things about other people in the office. You get to work with well known brands, but the low fees, non-exclusivity on jobs, low salaries and commission means it's not really worth it. No progression, training is terrible, Directors are dinosaurs living in the past and the culture is incredibly false and pretentious. Commission is below market rate. The client list is good, but the good clients are account managed so unless you have been there years you won't get to work with them. You will be dealing with the scraps.