Pros
Working for larger companies that have recognizable names while retaining the benefits of being part of a smaller organization, such as getting a hold of a higher up when there is an issue or if you have an idea.
Career Flexibility - if you demonstrate drive and aptitude, new opportunities are presented which can allow you to define your career and try new things. Opportunities to learn are embraced as an investment in you and the company. New experiences are more difficult to find working at other companies.
Communication - the previous pros are due to this: you can talk to the owners and upper management at the company about issues but also about yourself and the direction you want your career to go. Rather than feeling lost in the sea of a giant company, you will be a valued member of a focused organization. They want to hear new ideas and they want to hear criticisms. This gives you more control over your own career.
Cons
Job availability based on market, as it is for everyone.
Your own flexibility can be a limiting factor. The job you want may not be in the location you want or available as quickly as you need it to be. This is a reality everyone must contend with.