Honestly, there isn't much-loved you are missing out on in this update. I do however feel like it is slightly snappier and when you press the recents capacitive button, it is now almost instantaneous in terms of how fast it responds to input compared to it sometimes taking 3-4 seconds before the recents would pop up. Most of the tweaks to this build were probably security tweaks, possibly factory reset protection and some updates to Knox, but there's no way to be certain until they release a change log for it. It is possible they won't release this version and may push out another version entirely different than this one too. Or, this was just released accidentally via Samsung through the Kies software and that's why it is now pulled? This is an official firmware though as it shows in th e status of the phone, so it is possible they still may push it OTA at some point or move onto another official build. Did you by chance happen to tell him the build (LRX22C.N910VVRU2BOF1)? The kernel build date is Tuesday June 16th 9:48:12 KST. It is possible they still don't have it in their possession too, so we will see what happens.
