Pros
Colleagues are outstandingly competent. Everything is arranged to make you feel happy and productive. Flexible hours, smart working, unlimited holidays and hours off (use them responsibly!). You're judged on results, not on hours worked. Lunch and dinner (if you want to stay) are provided in the office. Fridges are always stocked full of treats, coffee machines are always loaded and ready. Amazing initiatives like an annual retreat. The best hardware and software with brilliant internal support. Salary reviews keep your career moving. Stock options allow you to invest in a team of brilliant people and feel like an investor, not just an employee. Everything is transparent and everybody is positive and motivated, no worries about drama or office politics.
Cons
If you want a 9-5 relaxed life, it might not be for you. If you love what you do and want to do it for a brilliant company who give you all the tools and opportunity you need, apply. You need to be open to feedback. If you're overly sensitive or don't take criticism, it may be a tough adjustment.