Some readers may have some answers for you but just wanted you to know that CNET probably has the best information out there on Digital Audio, mp3's etc.
There you will get the expert audiophiles and they will be able to sort out you dilema.
I bought a Palm T/X and I'm happy with it in most respects. But I am an iTunes user, so its incompatability with iTunes renders their music playing feature useless. Even with an expansion card and a third-party program, I have not found a way to download songs from iTunes or CD's from my Mac (OS 10.3.9) to my Palm T/X.
The Palm T/X needs audio files in an MP3 format and iTunes formats their music in AAC format (I think). I've read the Palm user manuals and forums, and apparently there is no way to format music you bought on iTunes so that it will be read-able on your Palm. I also bought a program called mOcean, which claimed to make iTunes compatable with the Palm T/X, but after I bought it, the user manual stated that it could not convert DRAM files, which are the kind that iTunes uses. mOcean's documentation claims that you can upload CD's of your own, format them as MP3's, and then download them to your palm, but the two CD's I've tried have also not had music in MP3 format, and I have not found a way to convert them. So far, the only song I've been able to download to my Palm has been an MP3 that a friend emailed to me.
The Palm documentation and sales pages don't explicitly state that their product is not compatable with iTunes, so I wanted to clarify this for other prospective buyers. It has taken me several hours, $20 for mOcean, and $30 for a memory card to realize that the Palm T/X has many other uses, but that its music player is essentially not functional for iTunes and Mac users. Maybe someone who is better at reformatting files has found a way around this, and if so, I'd love to know about it. Otherwise, I'm hoping that I can save some other iTunes users some time and money.