Difficult. I can detect differences between them. I remember I conducted a test between two files ack when choosing the bit rate to use for my library. I was comparing kasbians club foot between 192 and 128, and all of a sudden, click- I could hear the waterynessif the cymbals, It is a lot more difficult comparing between 5 samples especially on iPad ( with earphones of course). I think they are in descending order- I think the tell tale sign is the cymbal crescendo around 1:12. It's damn difficult- there is a difference- I could tell between two directly, maybe three, but five is just confusing me- I can't hear enough slight difference to rank them!

I still have only 1gb of RAM in both my computers.