Vantaggi
I worked at SwiftStack for almost 4 years. Had a great time, worked with great people, traveled, met with plenty of happy customers, and had enthusiastic response. Smart team members, and felt like people always had my back.
Left on good terms - simply had other personal project things I wanted to work on.
Svantaggi
Like any "small" company, many of the enterprise customers have higher demands and expectations than what you can ever possibly do. Part of the balance is knowing how to keep feeding them new features while not succumbing to every whim they ask for - you'd go out of business quickly. This is not unique to SwiftStack.
Technical decisions are sometimes made that I didn't agree with, but regardless I'm glad someone made a decision. Plenty of other places no decision is ever made, which is even worse.