Pros
Small company with lots of moving parts means that you can get your hands dirty and learn A LOT. Not overly structured but organized and responsive. Values employees and their well being as much as their clients. Fun office perks and lots of opportunities to advance. Clients from many different verticals means great exposure to all kinds of projects and tasks. Offers full benefits to all full time employees and the plans are great.
Cons
Small company means that they don't have the resources of a larger company, i.e. dedicated HR department. There are a lot of independent departments and roles that don't get to meet or collaborate as often as in larger companies. No 401K offered. Compensation is a bit low compared to industry standards but they work with you and offer raises based on performance.