Vantaggi
There's always new projects that could potentially be something that interest you, and the management likes to place people on work which they enjoy. A very lax schedule on office hours and a willingness to be flexible in terms of hours on-site location etc. Good health benefits, 401k no matching (yet), unregulated PTO, flexible hours, relax atmosphere, quality employees. Encouragement to grow as a developer, and offers tools, reimbursement, and mentoring for education in specific areas. Ping Pong for when you need it, good happy hours, moderately balanced work/life atmosphere, sponsored hackathons with prizes and potential investment from founders.
Svantaggi
The companies structure is a tad flat with not a lot of room for growth, other than possibly getting a pay raise. Sometimes extremely long hours (depending on the project), and the management tends to micro manage individuals especially on larger accounts. Resource allocation is a little bit scattered with senior resources doing a lot of heavy lifting to pick up for more junior resources. Tends to be a 4 to 1 junior dev / senior dev ratio. Which can cause some frustrations but this really isn't a major or really even a con, but something to note. They don't really "give" out bonuses. Which isn't terrible as a bonus isn't expected but an end of the year bonus would be REALLY helpful. Raises tend to be in extremely small increments and happen only annually. Don't expect to go from X to Y regardless if you're an amazing developer.