Pros
Arkham allows for employees to learn new technologies and software on the job and has a lot of room and need for engineers willing to explore new ground and pick up new skills beneficial for both you and the company. (Plus free snacks in the breakroom). The career opportunity aren't in terms of "moving up the ladder" as there aren't really any ladders. The career opportunities more lie in ability to learn new skills and move from software to firmware to hardware if desired or however you want to grow. That to me is more important that up some metaphorical leadership ladder.
Cons
1. No "work from home" options. 2 . Since company is so small, the amount of mentorship and direction giving is very dependent role to role. It's possible to end up learning, prioritizing and tasking your entire role by yourself. It allows for a lot of independence if that's what you want, but can be a little overwhelming to know where to start.