The 3Ds is still the best performing low-light camera (with the 1Dx just catching up).
That maybe. but the very fact that 1dx is pitted against at least three other dslrs - D800, D3s(?), D4 in shadow noise, Low light, God-knows-what-other-features in that order, in-fact, speaks a lot about 1dx. Don't you think?
Pitted against the d3s and d4 - at least on DxO - to me this means they are basically in the same league. This is actually good news, but not the kind of "trashing" that the thread starter hints at. Once invested in lenses, there is no reason whatsoever to switch from one brand to the other, at least not for the kind of work these cameras are intended for.
Landscape/architecture/interiours is a different matter. I made the switch for my own work last year, because the high DR of Nikons does make a significant difference in post-production. That said, we use a number of Canon bodies in our workshops, because much better price/performance ratio, and better availability/service where I live.