Pros
I've been with WriterAccess since 2013. Some years, I've done a lot of work for them, some years I didn't pick up any jobs from them at all because I was doing other things.
But I'll say this: They've been there for me, through thick and thin, when I needed work. As of this writing, I've delivered almost 2 million words for them.
The staff is super easy to work with. You're dealing with real people, not nameless cogs like with other content providers. They've been patient with me through illnesses, ADHD, etc... Sometimes I've been a PITA to work with. And they were still with me. When I was having an issue once, the owner even spent an hour on the phone with me, making me feel heard.
Kontras
The only con is that the amount of work they have available can vary. Before AI, there were a lot of opportunities, but we all know how AI has affected writers.