I came from a Note 3 and I like it, but not significantly better.
It gets better phone/data reception but wifi is worse, a lot.
I think the interface is better but whats up with the stupid 5 wide grid size, makes widgets look dumb with the giant gaps. Knock is awesome.
I do miss the S Pen on occasion, I actually think the G3 would be better equipped for the S Pen than the Note 3, for factory apps. The notepad, Qnotes(?), is way better.
Dual screen is worse, Samsung is way better, transparent apps is cool though.
The battery does get warm but nothing crazy. Battery life is better by a couple hours, 8-6 and has about 20% left. The note 3 would be on the charger, however the batteries were a year old.
However, finding batteries and cases is a pain, no one has them locally.
The stock music player is garbage.
The whole interface is smooth with no hiccups. I have had it randomly reboot a couple of times, but outside of my GN3 every phone I have ever had did that, including the almighty iphone.
And the main reason I chose it over the M8 was wireless charging, I am not to worried about a spare battery.
One huge bonus is that Google wallet actually works. So sick of Verizon boning us.
It's a phone I like, but is nothing super special. As to whether I would buy it again, no. The next gens are out now.