Whenever I hear someone, anyone, claim world's fastest, I hear world's most unstable.
I have a Asus RT-AC66U and I can say its the most stable router I have used recently. Had to replace my DLink that had issues with Outlook and Lync.
I am also very impressed at the power their stock firmware gives. Its a very powerful little router capable of a lot of great things.
With dual core and USB3.0, it seems a lot better than the RT-AC66U. I'm planning to give it a try. I just hope that their USB3 does really perform at close to spec of 5Gb/s.
The best you can expect is about 4Gbps since rated is max throughput without the drop off in encoding which is 8b/10b for USB.
Still its faster than a wired 1Gbps link, or even the 802.11ac max of 1.3Gbps, until 10Gbps routers become affordable as well as 10Gbps NICs become standard in systems which will be a while.