So I'd start by asking yourself why you thought iTunes sounded bad on your best source in the first place. It could be that switching back and forth a/b isn't yielding the answer you want is because this is a flawed way to tell subtle differences. The brain is a complex organ and hearing simply isn't as precise as going to the ophthalmologist and saying better or worse while looking at the eye chart. I won't speak for anyone else but for me it takes time listening critically to each source, and with different music. Can't be distractions of any kind, just you listening to your system. You may in time be able to tell quite a bit of difference, particularly between 256kbps and lossless. Give it a chance. I have been chucking all my MP3's over the past few years for lossless, and am finding even more clarity in the higher 24 bit offerings. You can always rip 256 kbps for the phone and car but I think you will want better for your best system than that.