Pros
First and foremost is opportunity. Its a small company at which good work is not overlooked and proactive people are rewarded. You will not be a cog in the machine at Perceptronics. The work is also really interesting. This type of research and development work is very hard to come by. Not surprising that the people are by and large hard working, smart, engaging, and fun to work with. Employees have a surprising amount of input on a lot of things.
Cons
The work can be a bit chaotic. I personally don't see this as a con, but I think that some people do. If you have a hard time changing gears on the fly or working under uncertain / changing requirements then Perceptronics (or R&D in general) are probably not for you. The openness and flexibility that I described under "pro" can also be seen as a con. People who thrive at Perceptronics are typically those that feel comfortable advocating for themselves and their positions.