Had been thinking about putting in order for the Airport Extreme Base Station in the hope that I'd get a better wireless range in my house (I have no phone connection upstairs where my iMac is). But - and this is yet more evidence of how clueless I am - now wondering should I be getting the Time Capsule instead? I've been reading the specs and all but I'm still not really sure if it's basically a backup device that also does the job of the AEBS? Is that what it is? Or am I talking manure? Would appreciate your help.