I think you're fine so long as that cable can read the 20GB drive even when not connected to the console. I'm betting most of that info is from before the 60GB model came along.
I can't really imagine why it wouldn't work so long as the amount of data you're trying to copy is equal to or less than the total amount of free storage space on the other drive. And if you have a 20GB drive you're looking to copy to a 60GB drive, that should satisfy the requirement.
I have recentley purchased a 60GB xbox 360 hardrive, but previous to this I had a 20GB xbox 360 console premium pack - I therefore want to transfer my gamesaves and other items to my new hardrive -
I have found many hard drive transfer cables on ebay such as the following:
http://cgi.ebay.co.uk/XBOX-360-DATA-TRANSFER-CABLE_W0QQitemZ350236015750QQcmdZViewItemQQptZUK_VideoGames_VideoGameConsoles_VideoGameConsoles?hash=item518bb17c86&_trksid=p3286.c0.m14
But I'm slightly confused/unsure about there compatibility with my situation -
I've read that they transfer data from a 20GB to a 120GB but will they still do it from a 20GB to a 60GB - I've read this information about the 20GB to the 120GB from the xbox.com website so I wasn't sure if it was just microsoft playing with my purchase choices
To sum it up my question is:
Will the xbox 360 transfer cable work/transfer data between a 20GB and 60GB hardrive?

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