The LG G6 was a definite improvement over the G5, but it wasn't quite as impressive as the Galaxy S8 overall. However, the price of this phone has been dropping ever since launch, and now you can get a new G6 for $150 off. Amazon is now selling the unlocked LG G6 for a mere $549.99, matching a previous deal at B&H. The GS8 is a lot more spendy.
This device is the US unlocked LG G6 (LGUS997), so you have a warranty and all the bands you could ever want. It works on both GSM and CDMA networks with LTE bands 1, 2, 3, 4, 5, 7, 12, 13, 17, 20, and 25. Inside, it's the same as carrier versions of the phone with a Snapdragon 821, 4GB of RAM, and 32GB of storage. The display is 5.7-inches with a resolution of 2880 x 1440, which is taller than most phone screens.
Amazon also offers a monthly payment plan on this phone, so you can pay $110 per month for five months instead of paying all at once. The phone is available in either silver or black, but the black looks much better.