Hot Hardware published a review on the Rivet Networks Killer E2500 Gigabit Ethernet For Gamers With Advanced QoS Tested A quote from the article:

Rivet Networks recently announced its latest Killer networking product, the Killer E2500 Gigabit Ethernet Controller. For the uninitiated, the very first Killer Networking cards were introduced way back in 2005 and were designed to maximize throughput and minimize ping times for gamers. While total throughput is often similar between network controllers today, Killer networking products reckon they can still deliver a superior experience through improved ping times and quality-of-service (QoS) prioritization. We have had hardware in hand for a while now, have put it through its paces, and can offer some insight on the Killer E2500's actual benefits. Check it out...

 Rivet Networks Killer E2500 Gigabit Ethernet For Gamers With Advanced QoS Tested @ HotHardware