Tried the LG G6 and here are my initial thoughts:
Screen is very impressive. Full brightness is very accurate and isn't too saturated. However, auto-brightness seemed very dim compared to the GS8/GS8+.
Idk if autorotation wasn't working problem on the YouTube app when I used the demo model, but I had to set that on manually on my own. The app also had trouble with the keyboard w/ the "X delete button" being close to the search button so it caused the demo unit to act up a bit. Swiftkey will take care of that though.
32gb internal storage seems too little as well. Good thing there is a SD card.
The processor doesn't seem bad at all. It's no 835, but 821 is no slouch. I haven't noticed any micro stutters or lagging. The UI isn't aesthetically pleasing, but it's not bad as the LG G3's UI set up. Not sure what's the point of the Q Slide. The facial detection
@MRU shared inspires confidence regarding using that in conjunction with the FP sensor.
The build quality is great. The black model seems better to watch videos on, but the silver one looks like a better device color to buy. The sound isn't too bad. I am definitely interested in this device. Time will tell if I get one.