Pros
Inexperience will be rewarded and land you a senior role.
Cons
The owner is young, has no direct contact with staff, and is not a designer, therefore the office lacks soul and is focused solely on maximizing profit. Generally speaking it is a toxic environment. The administrative staff is mean-spirited and vindictive, and are not familiar with design or the process of design. Expect to be considered a cog in a machine, not a designer practicing good design and who wants to sharpen their craft.
If you're looking for an environment to practice your design skills within a mentorship framework, this isn't the place for you. This is an office where inexperienced entitled individuals are given lead positions (there are numerous "Director" titles) and are therefore incapable of providing insightful, educated direction. If you are looking for an office that shows appreciation for your efforts, as in a year-end bonus, or a simple "thank you"... there won't be any.
The company fees are shamelessly high and they are always on the prowl for any opportunity to increase them via add service requests.
If still interested in this company, join knowing that you will be taking part in a process of "inexperience guiding inexperience".