I assume that you are formatted to NFTS.
I have just bought the Western Digital with the Media Card Reader attached but have only been using it and Dantz for two months and therefor not really able to comment.
My previous Maxtor X5000 lasted for 4 years before the kitten nudged it too close to the edge of the desk. I managed to recover almost everything, I think, but it was never the same again after that meter jump onto the carpet! So I replaced it.
Go for one with both types of connection, you may be able to download direct from your Camera. There are some 5400's out there and there are those faster than 7200, but probably quite pricey. Speed makes a big difference when transferring large files, so I have been told.