Pros
I have been working at Energy Focus for around an year. I believe it the most fun and energetic work place. The most important pros for me are opportunities, environment and job satisfaction. The amount of opportunities I have got is countless, with number of new projects coming, there is a lot to implement, learn, contribute and grow. It has very fast paced and ever changing environment yet very well balanced by the hiring team. I find no problem with work-life balance, working 40 hours a week is possible and most people do it. There are also few who are hyper-motived and work extra hours just because they love it, or because they're competitive.
Cons
If you are someone who does not like sudden change in priorities or accustomed working in a slow environment then this wont be a fit for you.