The sad part is, I don't see anything terribly contradictory in the last page- just different starting points for the same perspective. But I wonder if auxy hasn't already earned a vacation.
Oh, one thing that did stand out: 'you need more memory bandwidth to take advantage of more memory' -- while innately true, it still depends entirely on the circumstance. Typically, you don't need more memory at a particular latency/bandwidth level to do more things at once- you need more memory at a particular latency/bandwidth level to prevent the action of switching to one of the several things you're doing at once from having to reach back to memory with latency that's at least an order of magnitude higher or whose bandwidth is at least an order of lower.
You fix the problem either by a) adding more memory or b) making that next lower-level of memory faster. More VRAM helps GPU's keep out of far slower main memory across the high-latency PCIe bus, and as an example of the latter, SSDs decrease the latency and increase the bandwidth of main memory's next lower-level.
So, if we had GDDR5 on the CPU and GPU drivers that could account for the latency, which should actually be fairly easy, then we likely could get away with not putting so much VRAM on graphics cards. But we don't. We have DDR3, with DDR4 realistically over a year out, and DDR4 is both higher latency (from an absolute measure of latency in nanoseconds, let alone massive increases in per-clock latency) and not terribly higher bandwidth than DDR3- likely around a factor of two, which doesn't begin to close the difference in bandwith with top-end GPU GDDR5 implementations.
Which means that, yep, we are going to need more VRAM on our GPUs- both on average, to the tune of 4GB-6GB, and on the high-end, to the tune of 6GB-12GB. And no, Titan isn't high end. It's not a consumer graphics card. But Nvidia could easily ship a GTX780 with 12GB bolted on tomorrow if they so chose, and it'd likely cost them no more than an additional $20-$30 to manufacture over the 3GB model.
Canon 6D|24-105/4L |70-300/4-5.6 IS USM|50/1.4 USM|50/2.5 CM|50/1.8 STM|85/1.8 USM|Samyang/Bower 14/2.8|24/2.8 IS|Sigma 150-600 | C
Canon EOS-M|11-22 IS|22/2|EF-M 18-55