anyone listened to iTunes Plus on high end system?

Thanks Knownothing, that was the type of answer I was looking for. I believe my weak link is my speakers. I tried a comparison with a classical piece (cd version compared to itunes plus), there was more dynamics and air on the redbook compared to the cd I burned with the aac file. The first test was "hard rock" which was quite a bit compressed in the first place. It was harder for me to tell a difference. The 256 acc, however, did sound quite good and if I did not have the original CD, would have been quite happy. I hope HD tracks keeps expanding...and hopefully, Apple will have lossless downloads one day.

Note - just in case someone is tracking along - there is a big difference between what Abery is listening to - AAC@256 and what Knownothing is referencing which is AIFF (uncompressed format)

Absolutely no comparison

For what it is worth - it usually doesn't take a remarkably good system to tell the difference between standard iTunes 128kps AAC fiels and iTunes Plus 256kps AAC files. The Plus files usually connect the musical dots better in every way.