Actually these sticks are 7.9ns not 10ns - (17/4266*2000=7.9ns).I wonder why this is considered "ultra-low". Back in DDR2-400 days, fast memory was running CL2 (10ns latency). Fast forward 10 years, RAM is 10x as fast, but so is CL. So in actual real time, the latency is still ~10ns.
I know there are laws of physics and lowering voltage doesn't make capacitors fill up faster. It's the marketing terms I have a problem with.
You're also excluding the peak transfer rate in numbers which these sticks can provide while maintaining that lower latency being 34.1GB/a vs DDR2 400 being a mere 3.2GB/s. That's a factor of 10! Let's also add ontop of the fact that these sticks offer a lower operating voltage of 1.45v vs the DDR2's JEDEC being 1.8v.
Now add all the benefits together (Lower voltage, 10x bandwidth, lower latency) and compare it with your DDR2 400. We are certainly leaps and bounds today from what we could do in the past.