Has anyone stayed at this hotel? It has high ratings on Trip Advisor, but is not rated at all by RS. Thank you for a reply.
Remember that Rick Steves' Europe (RSE) does not intend, in their guidebooks, to "rate" all or even a significant portion of lodging options in a given area.
Rick's is a different approach from the guidebooks that attempt to rate a large number of lodgings in an area. He explains his approach to listing lodgings in his guidebooks.
What this means, in relation to your question, is: no negative connotation should be given to the fact that the hotel, as you said, "is not rated at all by RS." It doesn't mean Rick doesn't like it or has been there.
Yes, we stayed there two springs ago (2013) and really liked the Hotel Dersaadet. Fabulous location, great service, very nice breakfast in the dining room on the top floor with an amazing view. I would highly recommend this hotel and if we are lucky enough to go back would book there in a heartbeat.
If you make it to Cappadocia I also highly recommend the Kelebel Hotel in Goreme, a cave hotel- fabulous! And Cappadocia itself is fabulous.