Pros
This is a very employee driven environment -- if you have ideas and want to put them into practice, you can find a space to do a lot of exciting work. The teams are dynamic and open to change, young office, creative space.
Cons
The office feels like chaos somewhat often. There is limited leadership (it is an office that tries to be "flat" but isn't in practice, which can be very confusing). The goals for projects change frequently and sometimes without a lot of clarity. The work is mostly theoretical, this does not appeal to everyone. Managers are very limited in experiences, often don't take feedback particularly well or implement it. Some employees have more limited experience with research than others. If you want to learn research skills or hard skills, you will need to do that on your own time.