HDR is used as a last resort. Keep that in mind.

You can not get "perfection" unless you have the place properly staged, and you take the steps to have 100% control over your lighting. for RE in particular, lighting is 95% of your image quality.

Ultra wide angles are less desirable than stitched panos shot with shorter lenses. There are several images in this link - http://www.ctpost.com/realestate/article/Habitat-Eye-popping-showpiece-in-Fairfield-10904440.php#item-38492 - you provided that provide a false perspective view typical of ultra wide angle lenses, and there are other problems:
3
4 - I am sure that small table in the foreground on the right side is not oval-shaped
7 - the newel post seems to occupy 25% of the lower half of the image
8 - room looks too large, and the foreground has no-nos for RE - two pieces of furniture that are incompletely shown
10 - giant newel post again, better comp would show the bottom of the post, and the skylight - would have been included if a pano was shot and the camera was in portrait mode
11 - Lighting is poor, seems to come mostly from the camera's POV, ultra wide lens used which renders the left wall as huge and disproportionate
15 - UWA exaggerated extension distortion again, chair on left only partially shown
16 - table looks like a trapeziod than a rectangle - misleading, caused by UWA lens
20 - piece of plant hanging out on the right, base of table missing, a lower POV would have been better, and a pano, possibly even with this lens but in portrait mode, would have shown the floor and the ceilign better
21 - UWA distortion - lamp on left is huge and out of scale

And so on - this is nice effort - clearly by someone who knows lighting and how to use a camera, decent staging, but lots of composition/post processing errors, and too much use of an ultra wide lens to "fit it all in" when a stitched pano would have provided a more "natural" and perceptually more accurate rendition.

I suppose this kind of work is acceptable to the owner and the agent. If it were my house, it wouldn't be. For a $4M house I would expect images to match. These don't quite make the grade.