I'm close to purchasing a new router and am leaning towards the Airport Extreme. I don't really understand what this new "n" connection type is (vs the old b/g) and I know the extremes can run at 5Ghz and 2.4GHz simultaneously. My concern is, I know not all devices are compatible. For example, my iMac is almost 5 years old so I'm not sure if it is even compatible to run on "n"? I'm assuming "n" is faster? And I dont know if my iMac can run at 5GHz? I have no idea how to find out, but, i did a search in the "about this mac" section of my computer and this is what I found. Can anyone help me figure out what my old dinosaur is capable of? and can someone explain difference between "n" and the older b/g.