So, I just wanted to report that the more I listen to the iPhone 5S with a wide range of music the more I like it. Partly, of course, this may just be due to brain-burn-in, but additionally, it's definitely also at least partly getting to hear how the 5S handles more and more of my music library. And, as I say, I'm impressed. So impressed that I decided to sell my JDS Labs C5D as I've found that the extra bother of an outboard amp/dac just isn't worth it for the small SQ increase. I'm sure that would be radically different were I to use different, less easy to drive headphones, of course!
Anyway, I would say that what most impresses me about the 5S is the clarity and detail and dynamics. It's a forward and direct sound--and this may take some getting used to if you're coming from warm and laid-back--but it's well worth it to give the 5S a chance and to find the right pairing of headphones for your taste. Or EQ settings, if you go that route.
OH! And I also wanted to report that I tried the idea of switching the media type of my music videos to TV Show so that they could be organized and sub-organized (by artist). It was a complete disaster that ate up about two hours of my time! I would strongly urge people NOT to do this. Music videos do not fit well into this category and I could not get them to be organized the way that I wanted. Perhaps I was doing something wrong and perhaps the person earlier in this thread would want to detail how he or she did this.
But what I ended up doing was to change the type to "Home Video" and that worked perfectly--and it also allowed me to use the HD versions of my videos in place of the low resolution ones from iTunes. So, you still end up having all of your videos in one big list, but the advantage (in addition to HD) is that they no longer appear in the Music Player App as white albums with no artwork. That's one of the things that annoyed me most! Even AFTER having blanked out the album name and track number and volume number stuff, the videos STILL would appear in the album list! WHY? They can't be freaking played from the music player? Why should they be listed? I don't have any idea. But if you make them Home Videos (or TV Shows) then they will not show up.
And I will also say that one advantage of the iOS 7 player is that you can be browsing in artists while a song is playing and when the song ends and the next one begins it does not knock you back or make you lose your place. Indeed, your place is uniquely remember for each method of browsing, which is nice. Still, all in all, I preferred the music player and video player in iOS 6.