Pros
The project work was exciting. Upper management really stuck to their values when it came to the type of work and the process of doing the work (this is hard to do in the UX industry). The people there, besides the owner, are talented, fun, and overall awesome people. I made some life-long friends there.
Cons
The owner has a very bad temper that he unleashes on employees and clients alike. I saw a lot of client relationships fall apart because of him. This also led to an internal fear about the pipeline of work coming in. There is a culture of mistrust, which makes it hard to collaborate on design. The design process, while evidence-based and thorough, would often beat ideas to death. Design reviews were brutal and often left people in tears. I would consider this a toxic workplace. It took time after leaving for me to learn how to trust the people I work with, to not expect to be yelled at by my superiors, and to trust my design abilities again.