Ordered quite a few articles in the past for one specific field.
Speed: 10/10
Content 9/10
Revisions & Support 10/10 (revisions are done quickly and according to your needs)
Proofreading 8/10 (sometimes find one inconsistency/grammar error every 1000-2000 words or so, nothing to worry about, but you have to check everything even after the revisions are done.
Research 9.5/10
Value for money 9.5/10
Overall 9/10 (depending on your topic/subject it should be between 8.5 - 9.5). If the writers were native speakers and/or did just a little bit more proofreading, then it would definitely be 9.5/10.
Wouldn't hire such a writer to post articles/news on a very popular website and without my supervision, but if you are looking for content which you will double check before publishing - it is fantastic. If these guys will improve just a little bit more, they will have a very nice service (which is already quite great considering the positives).