[Cube] AirPort Extreme BS or AirPort Express?

[George Pepper]

Now that I have the Mini, I'm going to replace my old white AirPort Base Station (If anybody would like mine, e-mail me offlist).  Should I get an Extreme Base Station or the Express?  I can't figure out what the advantages or disadvantages for the Express might be: Is it just for piping iTunes around?  Not sure I understand the concept.  All of my computers have iTunes, so?

Pep