One thing to consider about Sony. I think they have the sweep panorama mode. If it works the same as in their point & shoot cameras, all you have to do is depress the shutter release, then sweep through your panorama, and the camera and software do the rest. I don't believe any other mfr. has got it so refined. Also, the body-integral anti-shake technology of Sony (and Pentax) is a huge plus to me. I don't have to buy it on every lens, because it is in the camera body. Not the case with Nikon and Canon. I have a 20 year old manual focus lens on my Pentax, and it still benefits from the anti-shake.
I think the Sonys will take Zeiss lenses, which is a plus.
As a real estate pro, you may want to look at whether you can get a tilt-shift lens for Sony. This lens will correct perspective issues when shooting architecture. They're damned expensive, so you may not ever want one, but I've always wanted one. I don' do enough serious shooting of architecture to justify it though.
Also, it is worth noting that just because Canon and Nikon are the best-selling, that doesn't make them the best cameras for you. When I was starting out with my dSLR several years ago, I also found that Pentax blew Canon and Nikon away. Better kit optics, better construction, body-integral anti-shake, and better backwards compatibility of optics.