Edanz sets and tries to maintain the highest standards of quality and does not tolerate substandard work or rude comments from its freelance editors. If this happens, after a fair probation period, such editors are let go - the minority of negative comments here are from such disgruntled editors. It's sad that they wallow in bitterness instead of just settling for working at one of Edanz's less stringent competitors.
Cons
There are relatively few cons of working at Edanz. I know some freelancers have complained about fees but these are competitive within the industry. The best way to make the work worth your while is to get faster and more efficient while maintaining quality.
Excellent on-the-job training in copy editing (with a particular focus on editing for ESL clients).
Professional and courteous administrative staff who are very considerate of their editors' needs.
Fee increases if the editing job takes longer than expected.
Flexible working hours.
Cons
As with all editing agencies, there is no guarantee how much work will come in.