There are a lot of threads on this topic. I loved the simplicity of itunes/iPhone sync but there's no substitute for androids. I tried a few diff. things and found the following method best fits what I needed. (smart playlist, large library transfer, tag editing, etc) Here's what I posted on other similar thread,
I just got done with my itunes library transfer. I too love the sync ability of itunes/iphone. S4's stock music player doesn't let you create smart playlist or edit the tags. I tried couple of syncing methods and music apps and found the following to be the best solution for me (for now)
Install a SD card, install EasyPhoneSync on your PC and S4, transfer your entire itunes library to SD card using EasyPhoneSync, install GoneMAD Music Player on your phone from Google store (found this to be the best app to edit tags/create smart playlist)
If you want to add any additional music files, you can connect your S4 to your PC via USB cable and copy/paste to Music folder: Computer\Samsung SGH-I337\Card\Music.
Took me a while to go thru all the setting options to personalize it but it was worth it!
gl