I'm a little confused about the airport express. Can I use it to replace my wireless router? Right now I have a cable mode box, which feeds into a VOIP box, then a wireless router. I don't have any computers on the wired ports, but I would like to occasionally connect one computer via hardwire. I guess the main reason I'm confused is that at some point I got the impression that the Airport Express had to be used in conjunction with the AirPort Extreme, but now I'm pretty sure that's only if you want to use the Express as a wi-fi extender. Lastly, is the Extreme worth the extra $70 if its your primary router in a home?