This monitor is almost identical to the popular 27GL850-B Amazon Deal for $649.00.
27GL83A-B (aka 27GL83A):
- 27" QHD (2560 x 1440) IPS display
- 144Hz Refresh rate
- 1ms Response time
- 1000:1 Contrast ratio
- G-Sync compatible
- 2 x HDMI input
- 1 x DisplayPort input
The LG 27GL850-B and the LG 27GL83A-B have very similar overall performance and any differences can be attributed to panel variance. The 27GL850-B has better inputs as it incorporates two USB 3.0 ports, while the 27GL83A-B has no USB ports.
The LG 27GL83A is essentially the sRGB color gamut version of the LG 27GL850 which has a wider DCI-P3 color gamut.
AFAIK, color gamut is more of a personal preference thing. Apparently this can also be important if you’re a photo editor, so you may want to look into this difference if this is important to you.
Therefore, this might be the monitor for you if you want it soon (click and collect from JB) and don't need the USB ports. Plus you'll save a few $$.