Pluspunten
I am a PhD and this was my first professional editing job. Papers had good variety and were usually interesting to read. Easily 50% only needed light copy editing and small number needed heavy work.
Work anywhere. Could easily block days of unavailability.
Rate was about $8/250 words.
They always were polite and returned my emails within a reasonable time frame given the difference in time zones. I never had urgent concerns or problems with a job. My email exchanges involved non-time sensitive issues. I cannot speak to how they handle an exigent crisis.
Minpunten
I was 'restructured' out of a job in May 2016. This was perhaps because I was a new hire (October 2015). I have no data about rate or other internal changes after the restructuring.
Even when I was working for them and asked for more work, I had a max of $400 per month due to volume. Perhaps after they reduced their work force, the remaining editors may handle larger volumes.
I am USA-based and because they are Japan-based, they can only pay me by wire transfer which resulted in $50 total in wire transfer fees. By opening a new bank account in their banking branch I reduced the fees to about $3 to $10.