If you are using Verizon as your carrier with the US996, you will also be missing the Advanced calling features of wifi calling and video calling in addition to the FM radio; something that for a phone touted as optimized for music/media is one of the main reasons I returned both my US996 and my Verizon versions, even though the audio was outstanding, IMO.
What you DO have on the unlocked version, which is also so awesome, is Google In Apps Search Shortcut for searching anything on your phone... try it. I almost kept the phone for that single, wonderful thing. Put it in your second display and use it a couple of times and you'll love it!
I didn't realize how much I missed the S-pen & waterproof of the Samsung, though. Like you, Samsung for years now.
If LG comes out with this phone next year, sticks a stylus on it, makes it waterproof, and negotiates better with Verizon so premium features are not disabled, Samsung might just lose a customer to them...
I miss the music... a lot...