For interiors we use multiple setups depending on the scope. For a typical home, I use a cage system with a 3 axis gimbaled GOPRO on it. The GOPRO has been modified to use interchangeable lenses since fisheye is awful. The gimbal is called a Rider. I like it because you can change how it connects to things, instead of it being on a stick/hand mount all the time. The cage has a rechargeable HDMI Liliput monitor on it, and mounts for mics and other things if needed. We have a DJI Ronin as well, and will also use a Blackmagic Cinema 4K EF production camera in RAW or Prores at times or a DSLR. This is by FAR a superior look, but the workflow is greater and the file sizes can get astronomical. Since Real Estate videos need to be quick and easy, we generally go with compressed footage from the modified GOPRO and the Inspire so that I can deliver the end product either same day or next day if needed.
We film everything at 4K 30FPS for the most part, since slow motion isn't usually a part of these videos. If anything, you'll notice I speed up transition shots a lot. This allows me to show more of the home without having to cut, and it's a pretty awesome effect. We actually used to literally take the props off the Inspire and I would walk around the home with it! People always comment that it feels like we flew the drone through the house, and that was kind of what I was going for.
Hope that helps!
Matt