Vantaggi
Can only speak to the research side. You will gain great research experience. You will become an expert at SAS. Acumen has a lot of great data. I only got to work on one area, but it seemed like there was a wide variety of interesting projects. While the skills are somewhat niche, they can be carried over to jobs at other research firms or in the health industry if you want. Most of the people you will work with are smart and are largely in their 20's. This can give it a sort of college or startup vibe, although without the perks. Its pretty social. The company is in the peninsula, but has a nice location right on the bay.
Svantaggi
Project management was particularly bad at Acumen. From what I could tell, senior management did not understand the importance of having a clear reporting structure and clear, timely direction. It was difficult to know who was in charge of the project at any given time. This led to miscommunication, missed deadlines, last minute work, and constant lurching from one strategy to another. These problems are especially prevalent in work involving the CEO. The stress from these problems leads many people to leave after a year or two. Conflict management is poor; managers tend to ignore problems or sweep them under the rug rather than dealing with issues in a mature, open and honest way. If you're looking to learn from or be mentored by someone more experienced, this may not be the place for you, as most managers, including some senior ones, are only a few years out of college. On the flip side, you can rise higher and gain more responsibility faster than you would somewhere else.