Party of 16 stayed at Johns place for a stag do weekend, the flat suited us very well as it was extremely spacious with a location central enough to easily walk to the Royal Mile. Ample sleeping space to accommodate everyone, however be aware with a party of this size you will have to queue for the shower as there are only two!
As a host John was extremely easy to communicate with throughout the stay, and check-in/check-out was hassle free.