I've unfortunately used mhrwriter.co.uk.DND. They take students for a rough ride through their other site too: essaysnassignments.com.

Utter scam, terrible spun content provided, despite half a dozen revisions which saw no improvement. The content was largely unreadable. For example, some of the Spun content changed company names like "House of Fraser" into "Place of Fraser", I found some of the original articles that had copied and spun, which I confronted them about, they still claimed it was acceptable content.

Total shambles.

UPDATE: TBH, I was being unfair, as I haven't actually used these writers. For all I know they are decent enough. All the issues have been rectified, they were actually quite open and honest and where quick to respond to a complaint, so I'm more than happy with the service.