Pros
The office is nice and well located. Salaries are good. Good place to learn if you don't mind the grind. If you're lucky you might get to work with some nice people.
Cons
The work is really boring. Always doing Magento, sites tend to all look the same to "save development time". The upper management does not have a clue how to manage an agency. The projects are always under-evaluated, which puts a lot of stress on developers. Features are added last minutes at no cost. Clients complain that projets don't get delivered on time, etc etc etc. In the couple of years I worked there, I have seen less than a handful of projets delivered. The office environment is really toxic and it feels like a lot of people are on the brink of snapping. Some of the most interesting projets are sold as if they are being made in-house but are instead offloaded to other developers in Europe. For all the above reasons, the employee turnover rate is incredibly high. If you like working with someone there, enjoy it while it lasts because they probably won't stay for long. Promises are made, like compensations and stuff, but never really delivered.