This is an interesting read about why using the Apple Music Store could be a bad choice. I have an iPod, but I'm only using MP3s on them, and have not yet felt compelled to use track-by-track online music stores. I don't really listen to any popular music, anyway, and the exceptions to that rule give me their CDs. ;) I actually prefer WMA over MP3, but the iPod can't play WMA, so I had to stick to MP3.
I hate lossy compression in audio. But I'd rather listen to music than not.