Pros
Company is generally young and inexperienced, giving you a lot of opportunities to take on a leadership role and shoulder some responsibility. Culture is generally fantastic. Easy to grab a bunch of coworkers and go for a drink and socialize. Most employees all live near work, facilitating social activities together.
Cons
Until recently, had a very flat corporate structure. They have recently been hiring people in more senior roles and formalizing teams within the company, but as this is recent there is still confusion about who reports to whom for a number of tasks and projects. For most positions, pay is poor. Unless something is client facing or an absolute necessity, it will not be paid for. Partners tend to splurge on office items that look nice and impress potential clients, but cheap out on items that will make the employees happy. Employees are treated more like commodities than assets. Once someone's been "consumed" and leaves, just pick up another one.