I'm guessing your in a office or something with limited computers?
I can't really say much about performance as i have never used the card, it performs better than other cards in download and upload tests.
After running the Bigfoot Networks Killer 2100 through the ringer, I have a fond respect for what it does. The claim is that it offers lower pings and higher FPS in games using UDP packet styles, which are the vast majority of online games out there that connect to the Internet for play. UDP is a connection-less protocol that spams packets onto the wire without first establishing a session or using a delivery confirmation method like TCP does. With the nature of UDP, if a packet gets lost it is not retransmitted, which if enough packets are dropped, then you start to notice a real interruption in your games. The Killer 2100 is designed to give your UDP packets first priority to the wire to help lessen the probability of dropped game packets. After seeing the tests, the combination of the hardware and the Killer Network Manager provided UDP transfers that were faster than both the onboard and Netgear discrete NICs.
The Killer Network Manager is one of the key components that make the Killer 2100 as good as it is. The software allows you to control the priority of packets from applications using your system's network resources, as well as the ability to control how much bandwidth each one is allowed to use. As an example, when I was running the tests with the Bittorrent application, I was able to throttle down the upload and download speeds to a maximum of 1Mbps, keeping it from using a lot of my bandwidth. This gave my game the ability to squeeze a few more packets onto the wire faster, which could mean the difference between my bullet killing my opponent or his killing me first.
While this card will not double your network speed, if you are hardcore into gaming and every second counts, then you will benefit from the abilities of the Killer 2100. If you are a casual gamer, then the onboard NIC will suit you just fine. The Killer 2100 is designed for gamers that put everything into their systems to get the most out of it. Think of it like you would your GPU — while some integrated graphics are fine for casual gamers, those who demand the best add better, discrete cards. Your network card is no different — if you are wanting every edge you can, then this is the card for you. I have seen it as low as $77 on some sites, which is a steal for the Killer 2100
Card offloads network communication from system
Increased network performance, especially for UDP traffic
Plug and play hardware
Application-level prioritization and control
The ability to turn off the onboard red LED
Real-time network and system monitoring
Integration with Fraps for FPS control
Does the BigFoot Network Killer 2100 NIC actually put? Is it worth it as a gaming NIC?
I don't view it as worthwhile, any decent NIC offloads TCP/UDP anyways, and it's a trivial amount of performance if it dosen't in todays system. Additionally, UDP is best-effort, meaning that "too bad, so sad" if a packet dosen't reach it's destination, it will just re-send. Faster than TCP perhaps (which is why it's used for VoIP and video), but not for things like Punkbuster which examine every packet (resulting in the dreaded "Too many packets lost" kick). Additionally, your ping times will generally be unaffected because that is dependent on your ISP and router more than anything else.