Workload:
Before coming I heard that they make you work long hours and you will never have a life. This is really only partly true. Most people do work long hours here, but its not because they are afraid of being fired. It's because they are truly passionate about what they do. The upside of working long hours is that management is very understanding if you need to take half a day for a doctors appointment. They know that you put in enough time and don't sweat the half-day leave. Your level of involvement is somewhat self-chosen, but the people who are interested in working here choose to stay late. There will be times when your project requires extra out of you, but that is the same for any salaried position...
Environment:
This is kind of tied into workload, but if you do not deal well with stressful situations, or you always need feedback and management, then this is not the company for you. You will be expected to be very independent and able to handle engineering and business decisions in the correct manner. If you are just "working for the weekend" then this is not the company for you; you will be miserable.
Compensation and Benefits:
The salary is somewhat below industry average. This is offset somewhat by relatively large stock options that are coupled with your base salary and vest over 5 years, but these aren't very liquid and when coupled with a high cost of living of LA, you don't have as much spending money as some. With proper management, this isn't an issue at all, I invest 15% in 401K and 10% in savings and still have plenty to live on as long as I plan well, but I'm not going to be buying an expensive car or anything soon. Speaking of 401K, they do NOT match. This is probably my biggest con, but I realize that its becoming more common for companies to forego this option. They make up for it somewhat with the company stock options, but they use stock options to cover both a portion of your salary AND 401K contributions so they double dip a bit.