Pros
Small company with a couple dozen employees, meaning you get to know everyone well from the CEO to analysts, and open door policy which is important and hard to find nowadays. These guys have a good heart for their employees - so long as you deliver and understand that the company's success is contingent on your personal success in doing your job. There's also a lot of growth potential from a technical end (due to exposure to many customer environments), but also from within if you can get roped into new products and such.
Cons
If a bigger customer project needs you, that becomes your only focus; smaller or internal projects that you are working on or have put an effort into can be shelved or scrapped entirely.