Pros
Small enough that you can recognize most people and not get lost in the crowd. Hasn't succumbed to the open office layout fad so you get your own personal space in which to work in peace. Working in a technology space that few have succeeded in. Fairly low-pressure work environment by Silicon Valley standards.
Kontras
Strong internal resistance to changing the legacy tech stack. The flip side of a low-pressure work environment is that getting deliverables from other people is often a struggle. The backend software release and deployment process is very error prone and a fear-based change control system has morphed around it. Only 8 paid holidays a year. Employee perks like 401(k) matching, etc. are minimally competitive. Upper management considers R&D merely an expense to be minimized rather than the core of the business.