Pros
There are many people at PNAS who appreciate constructive feedback on both personal and professional levels, and they sincerely want to make a positive difference. As others have stated, yes, at one point, the journal suffered from internal problems, mostly due to poor management and a lack of communication. However, when such problems were acknowledged and officially brought up to those with the power to affect change, necessary changes were implemented and situations improved significantly. Initially, there were issues related to professionalism, respect, and the sheer amount of work that employees received. However, workloads have since become manageable, and employees are no longer "talked down" to, but rather are included in department conversations. PNAS, which has always been a well-respected journal, has also become a great place to work -- but you need to be proactive if you run into issues. The journal has also made major strides in acknowledging diversity issues, both in terms of its content and work culture (it even has its own diversity, equity, and inclusion committee, which is very active as well).
Cons
See "pros" section for more information.