Yep, I have one of these. Built and currently displayed on a coffee table in a corner of my SW room.
Yes, it takes a whole coffee table roughly 2' by 4' to display this thing, it's that big.
I have not had any of the sagging problems that I have seen other people report. Mine has been sitting there for several months now and looks the same way now as it did back when I first built it. The only thing I could possibly think as to why some sag is maybe they aren't making sure every piece is firmly pressed into place. Especially when it comes to all the plates that are used in building the hull. If you aren't pressing those together firmly, I could see how sagging could happen due to the weight of this thing.
I'm not so sure this will ever show up in retail. Due to the hugeness of the packaging, the retail price of it, and seeing how retailers got burned by other larger expensive sets like the UCS Yoda and RBR, I have to think that retailers may shy away from a set like this.