Pros
The reviews that are positive here reflect recent changes. It is true that because of the company's small size and recent history of losing many employees (some due to unfortunate hiring decisions, done partly out of the need to get more staff to handle how busy the company was), the management is now deeply invested in keeping its staff happy. This is a recent change and should not entirely be trusted. The small size means that one gets a full-range of experiences in project management and research. The co-owner and some of the more senior management are experienced and knowledgeable, and there have been efforts to start sharing that experience. The company is busy which means there's a fair amount of job security if you do your work attentively and can tolerate the occasionally erratic moods of the head of the company. There is a desire to do projects creatively, though sometimes this is understandably restrained by client interest and limited budgets, which is often the case in any company. The employees are smart and serious, but also willing to be social and have fun.
Cons
High employee turnover actually reflects problems with how employees have been treated. A couple of reviews note that review process at the company is fair, this is not actually true. There was (in the past, at least) clear favoritism and arbitrary treatment of employees. Bonus potential is generous, but withholding bonuses has been used as a reactive measure that seems highly inappropriate in an otherwise rigorous and empirically-oriented company. Time off was not distributed evenly and further reflected favoritism. For example, in spite of being exempt employees, I was told that in order to go to a doctor's appointment I would need to use my PTO, yet the company happily expected its employees to work 60+ hour weeks with (again somewhat arbitrary) little to no comp time offered.