Pros
Fair wages based on skill set
Interesting work and client base
Owner committed to success of the business and his employees
For a very small company, you can trust that you will get paid and be treated fairly
Good place to learn new technologies and expand your skillset
Cons
Small businesses are different than large corporations and many employees expect big company treatment and perks that simply cannot be had in a small, sole proprietor business. No growth opportunities because there are no positions other than owner and employees. You can make more money if the companies profits grow, so you should have that mindset going into the job. If you want upward mobility, find a bigger company or start your own business.