Pros
First and foremost are the people. The company has some of the brightest, technically competent, and self-motivated developers I've ever had the pleasure to work with. The company plans several fun events throughout the year, which really sets the tone for the workplace. This is a relaxed, laid-back, fun group of people who get amazing work done. The tools and technologies employed are generally current-generation (people were upgrading to Windows 10 and Visual Studio 2015 when I left). You are given a lot of latitude when it comes to development tools and preferences, as long as it works with the automation processes employed (like the source control system, for example). The work is varied and interesting. Everyone strives for improvement and everyone is encouraged to contribute in ways that may be outside of their title (such as writing for the Dr. Blip blog on the web site). Thursday afternoons are "Teach Me Something" days, when employees use a conference room over lunch to share the things they are working on or find interesting in their off-hours. The breadth of knowledge in the company is incredible. Finally, management is easy to work with, there aren't any "silos" (it's a small company after all), and it's easy to fit in and feel like a part of the group.
Cons
Some of the customers can come up with some pretty random requirements at times, occasionally causing unplanned work and schedule confusion. This is fortunately a pretty rare occurrence (at least it was from my perspective as an engineer). There aren't any annual bonuses or stock grants or anything like that. The salaries are competitive, and the benefits are in line with other area employers, but something extra around the holidays would be nice.