Yep, MS's memory setup was design to allow for a large amount of RAM for OS funtions/ads/Kinect/bloatware. Sony's setup is designed for pushing graphics.
There's no way to make that claim until we know more details on durango's ram setup.
For all we know so far the setup is a extension of the 360, which allowed it to have a unified pool of memory, shared between the cpu and gpu, slower than the xdr on Ps3, and still go up against it fairly well, despite having less than half of the bandwidth Ps3's gpu could access for data.
For example, in a 60fps Rsx could in theory access all of it's 256mb of ram and all of the 256mbs of system ram, while 360 would be able to access about 330ish... But the gap was nullified, because since ps3 had to share that bandwidth for both data and framebuffer it turned out to be a disadvantage in most cases. Granted, the gap now is more than 3 times, where this gen it was only 2, plus not only the proportion has increased, the amount too.
But to say each of them is better we need to know whether durango's main memory's bandwidth will be enough and whether Ps4's memory amount will be enough. Right now we don't have the answer to neither of that. It would help if we had any estimate of how much memory high end pc games use for streaming buffers, immediate rendering, other graphical features, etc...
But I gotta say, if durango can actually access 2.2GB per frame at 30fps, i don't see orbis having much more memory than that to actually show it's bandwidth advantage... At least not at 30fps, for 60fps durango would be much more limited with just 1GB of ram...