Very positive environment and work culture. You can get things done super quickly and using new tech. You can instantly have a huge impact, leverage a bunch of resources and learn a ton if you want to.
Cons
If you like to work, none. Sometimes people move too fast and break things, but this is part of every startup culture. It's definitely not a place for 'coasting' or if your main priority is work-life balance. You will be pushed.