Mike Kelley has a nice article over at Fstoppers.com comparing HDR vs Flash for shooting interiors.
Mike's discussion of this subject is part of a classic continuing discussion (similar to the meaning of life) that goes on among photographers that shoot interiors. There is no one right answer, it's about the results you produce. Mike's key criticism of HDR results is, "the colors are way off, the window frames are all gross, and it looks like there’s smoke damage throughout the interior due to the program struggling to separate out the lights and darks and Mid-tones are very muddy."
After looking at HDR work of a lot of real estate photographers my observation is that out of hundreds of real estate photographers that use HDR, I've seen only a small handful that are able to finesse HDR so as not get those off colors, dirty looking window frames and smoke damaged interiors that Mike is referring to. It takes a lot of work in post. It's possible to control HDR, but it's hard and very few can do it. This is why I recommend that beginners use Exposure Fusion/flash hybrid if they are going to do shoot bracketed exposures and then grow into multiple flash technique as they feel comfortable with it.
Mike calls Exposure Fusion "HDR Fusion". That's not really correct. Exposure Fusion is a completely different algorithm (it's an averaging algorithm) than HDR. HDR uses a tone mapping algorithm and Exposure Fusion does not. The only similarity between the two processes is they both use bracketed images as input.