A useful source of links to other material which is well-curated by Rex Duis, a long-term campaigner around issues connected with the Property Guardian model. His main aim is to improve standards rather than throwing the baby out with the bathwater, as some of the more hostile elements seem keen to do. This is consistent with the EHN approach.
The Facebook page now features a 'Proposed Charter Guidelines For Property Guardianship Services Regulation In Great Britain 2016' which is currently the best source for the range of issues that the property guardian model throws up. It includes numerous real-life examples and features a wide range of proposals.