Pros
It's unique to other agencies in terms of culture and environment. Everybody gets along very well because it's not too large, nor too small. Overtime hours are a lot less frequent and drinks are always available after working hours. There are a lot of bars, restaurants and retail stores nearby so there's no reason to be hungry or bored during your breaks or after work. It's a relatively smaller agency, so getting exposed to different functions of the agency is normal. I learned what I could learn for years in a bigger agency within a year at ETA. Management has a pretty good judgment in terms of compensation (compared to industry) as long as you work hard for it. Everybody gets to celebrate their birthday in the office with free lunch (for everybody) from restaurant of their own choosing with extra pocket money.
Cons
Employee turnover rate is high, but advertising professionals are actively switching from one agency to another. If you're not a thinker, willing to work proactively and wear different hats, this is not the place for you.