Pros
They have a well-known client, Google, with great projects. Depending on the team, if you are lucky you'll find yourself in a really friendly atmosphere where you'll always be helped. Culture used to be amazing, that kind of culture that everyone was feeling proud of, however, in Jan 2015 everything changed.
Cons
Since it is really dependant on Google, everything they ask for needs to be done, even if it makes no sense, senior management will push everyone to get it done, even if it's something completely random. There was a massive loose of talent as per the pressure from that random projects, everyone was going crazy. If the "cool" party crowd accepted you in their group of friends you would become well-known and recognised. If you are a more shy person, there is no room for you at Essence, or if there is, you are not going to grow. There is a culture of "showing off" so if you are an introvert, it is going to be hard that the senior levels recognise your work, even if you are the one who work the hardest.