I wouldn't take their latency numbers too seriously since their measure isn't relative to the throughput. It's not always obvious, but the latency of high performance is tightly coupled with throughput. The latency of high performance systems is the server side execution time (for Redis that is a couple of microseconds), the network hop (probably a couple of hundred microseconds), and the congestion on the server (this is the time it takes the server to actually getting around to processing your request, since the server probably needs to handle other requests first before getting around to yours). The congestion, is directly tied to the throughput.
The most useful measurement I've seen is you pick a latency target, and evaluate how many QPS you can send to the server that meets that latency target. That gives a fairly simple dimension to compare to.