Been using the red leather G4 for slightly more than a day. Leather feels good!
Awesome phone!
Generally, the UI is faster than s6 by a little although there are some rare lag which is less seen on s6.
Battery is like 10% better than s6 on heavy non gaming usage for my pattern, I expect the batt to improve after a few more days.
Camera is great, just find it funny that it does not have focus lock
One inquiry for bros and sis out here that had been playing with g4,
Does your G4 heats up a lot?
Mine heats up noticeably although still bearable when:
-browsing chrome for like 20min straight
-take burst shot on camera
-multiple apps update
A lot more than s6
Heaty little fella