The shield on the 1804a is very light. The Mogami advertises superior shielding. Though it is a spiral shield, and may be more prone to opening up than braided shield if used hard or kinked.
Another factor that hasn't been mentioned is the type of insulation on the conductors. Though neither of those is teflon.
Nobody on this site has ever posted a comp between quad and non-quad balanced cables. That might be interesting... especially if one of the comps included a source of rf interference.
I have silver teflon cable in quad configs and non-quad. I don't like the general stiffness for short runs. Some of that surplus cable is way too stiff due to the construction (strand diameter, etc). I've seen cables made with that stuff that always wanted to coil and were a handling nightmare..
My go-to cable is a 25' pair that is heat shrinked together at 6' intervals and contained in a single piece of techflex. I like my short 1804a cables, but at 25', that cable is a dream. The slickness of the outer jacket allows the cable to float inside the techflex when coiling. It takes some careful assembly to get that right (you need to straighten the cable before heatshrinking, etc), but that cable handles really well. It lays straight, coils easy, it is extremely compact when coiled... Love it. I'm not sure cable with non-slick jackets could behave so well.
I find 1804a a bit prone to twisting and kinking because it is so flexible.