If your router is set to 2.4 Ghz Channel 6, then the adapter will connect to it on Channel 6. In reference to your question about channels - modern Wi-Fi adapters, in a Windows environment, automatically use whatever channel the AP that they are trying to connect to is using.
Even if you completely ignore the Killer Performance Suite, the default settings can make a world of difference, provided you have set the network speed correctly in the "options" window. What stands the Killer adapter apart is the network prioritization features, which are not only useful for gamers, but anyone that might need to prioritize network traffic in order to make sure any particular application, or applications, receive the lowest latency and highest throughput possible. It uses the 802.11ac standard and we have tested it with many hardware configuration and gateway combinations. The Killer 1535 should be just as fast, if not faster than, any other current Wi-Fi adapter. If you are using the Killer Control Center (or any performance suite), however, you will want to keep with the latest version of the Killer Control Center as we are constantly adding program detection rules, so that we can better prioritize traffic. If you are getting good results with your current driver, there is no reason to update. It was only released to address a small number of issues that were being experienced by a small number of users.
#Killer network drivers without suite update
This driver update was not a major revision.
If you are using the driver-only package, the effect from going from 12.0.0.312 should be 12.0.0.318 should be negligible, unless you are experiencing issues. Our normal account doesn't seem to be working - I'm going to poke Dell on that shortly - but I can help you with any issues that you are seeing with your Killer Network Adapter.