Did you see it says, "Discontinued"? Hahaha... guess it wasn't so popular after all.
They still have some other NIC
http://www.bigfootnetworks.com/killer-xeno-pro/All that is of source complete bullshit, only thing good nic can reduce is latency from PC to "nexthop" usually ISP router which on 100MBit ethernet is like 0.2-2 ms
64 bytes from 192.168.2.1: icmp_seq=1 ttl=64 time=0.200 ms
64 bytes from 192.168.2.1: icmp_seq=2 ttl=64 time=0.210 ms
64 bytes from 192.168.2.1: icmp_seq=3 ttl=64 time=0.413 ms
64 bytes from 192.168.2.1: icmp_seq=4 ttl=64 time=0.207 ms
64 bytes from 192.168.2.1: icmp_seq=5 ttl=64 time=0.211 ms
its from linux, maybe on windows that "killer" nic would give 1-2ms tops. And it won't help when gamer's sister starts downloading youtube movies thru same connection (good router with software like Tomato or DD-WRT can tho ;] )