Have you ever done a post on what is the best in-camera HDR and if it is an acceptable quality for real estate photography?
The best answer I've found is over at Slrlounge.com. The video to the right answers the same question. Their answer is the Canon 5DMkIII is the best because it has an effective mechanism for shooting a series of brackets and it keeps the RAW files that are used for creating the HDR result so you can reprocess if you choose. Most other cameras don't do that.
The second part of the question, "... is it acceptable quality for real estate photography?" has a lot to do with your taste and which processing mode you use, so there isn't a definitive answer to that. When the 5DMkII first came out several readers showed me their results from in-camera HDR and they looked acceptable to me. The rendering was restrained and not over the top.
Are many out there using in-camera HDR?