Theres been another review that has touched on this, but its tough to put it under a con - I certainly don't think it is, but to many it maybe so I'll put it under here. Some people don't operate well with the complete autonomy you have here. You have to be self motivated and reliant or you wont succeed.
Theres pressure to succeed as everyone relies on each other. Don't have enough sales for one contracts are up? It's possible an engineer is being let go. Like, next week. Its also totally possible for an engineer to tank a contract (I haven't seen it) but, again its possible, and it could have massive impacts on other individuals.
It's honestly the trade off of actually having a meaningful contribution to a company.