I got to test one today for a whole hour!!! Wow!!!
Quick summary:
1. The display looks fine. I did not notice the sharpness issue, but did look for it with different content. I had to balance that with other things I was doing though.
2. I did not notice any "lag" different from any other stock device. No better, no worse.
3. I like the UI and options better, compared to Samsung.
4. Design and feel are about as good as can be done for a 5.5" display device.
5. Very much prefer the button design of Samsung over the Google driven display nav bar. That said, the "immersive" mode works much better than the M8 effort and works with more apps & UI better. M8 seems cumbersome in comparison.
6. The device got very warm when gaming- especially the display area. Overall, the device gets as warm/hot as my S4. It actually reminded me of the very warm running Droid X2 that used a Tegra 2. The DX2 display got "hot", but due to the Tegra 2 pushing heat out. The DX2 was an AWFUL device, but the G3 is not. The DX2 was hot all the time and not just for gaming. It really sucked.
7. If I had to pick between the G3 and M8, I would pick the G3 due to much bigger display for same height device, better (for me) immersive mode and replaceable battery.
8. I tested Dead or Alive ++ to test the CPU out (MAME does not use much GPU resources). The game was significantly slower than on my also high res Note 2014. It seemed to be throttling down.
No time to test battery, more throttle conditions or radio reception. I can say that I am solid on the feeling this device is a better device for light to medium users and not for heavy users.
One revelation I had was the 805 will help with pushing Qhd, but still 28nm and like the Note 2014, the big resource and heat maker is the display. It really hit home testing in person. The display is mutually both a blessing and a curse.
Edit: I removed one "and" that read "and and" in the second from last paragraph.