> if my friend goes ahead and buys a Mac Mini for MOS3 on it... what sort
> of speeds will he get? Or there is no way to know this until he buys it?

If you read this thread you'll see that some people (including me) say that about 500 kByte/s is the maximum there is to get with HTTP downloads, but you'll also see that there are some users who for whatever reason experience a significantly higher download rate with their setup. The reasons for this discrepancy are yet to be determined.