Pros
Cutting edge technology: They are pushing boundaries in multiple industries, which doesn't make for a dull day!
Distributed working: They're quite happy to employ the right person irrespective of location. Also from what I've seen are flexible in working arrangements depending on individuals needs.
Lovely people: It's a positive culture where people push as a team to deliver outstanding products. I'm happy to say if there are any egos, they are left at the door.
It's a startup: Rapid progression as the company grows is all part of it
Cons
It's a startup. You're likely to be exposed to areas of work you haven't done before. I personally love that because it's an opportunity to learn, but I guess this may depends on the individual.
The amount of holiday is the least of any company I've worked for, but only just and you can take unpaid leave. I'm assuming as the company grows the benefits will get better because you have to make money before you can spend it.