Pros
Working at a smaller company is great because you don't have to tunnel through mountains of bureaucracy to get things done. Things at Lytro move fast, and you can definitely impact the company because it is so adaptable and nimble. If a newish engineer has a great idea, he or she can take it directly to anyone - even the CEO. There's no need to submit ideas to committees where they will languish. There are also great perks like a free shuttle to the Mountain View Caltrain station, catered lunch, free snacks, ping pong and a pool table. There are weekly happy hours and occasional evening events, like pub quiz, which are well attended. Management has been very responsive to requests for change. For example, for a long time we only had the ping pong table. After employees expressed a desire for another option, lo and behold a pool table arrived.
Cons
For some people, being at a start-up can be too stressful. Problems that would be small elsewhere, like a shipping delay, can be big problems here. Also, there are many people in the company who have to wear multiple hats. This is true in engineering, ops and G&A. I personally liked this since I enjoy variety but it may not be for everyone.