When one is interesting in a product, they should first identify the metrics they wish to prioritize.
These are my metrics:
IPS
144hz
27"
Displayport
freesync
IPS & Displayport - for photo editing
144hz - to mitigate ocular migraines.
Added, metrics to narrow the search 27" and freesync
Freesync cost less than Gsync and for photo editing, I figure why spend the extra money.
Interesting my search came down to three monitors. Which one is the best?
Acer XF270HU, IPS $600, 27" (2560 x 1440) 144 Hz DisplayPort AMD FreeSync $520 https://www.acer.com/ac/en/US/content/model/UM.HX0AA.A02
ASUS MG279Q Gaming Monitor - 27" 2K WQHD (2560 x 1440), IPS, up to 144Hz, FreeSync. $537 https://www.asus.com/us/Monitors/MG279Q/specifications/
AOC AG271QG 27 inch IPS 165Hz DisplayPort 2560x1440 PX G Sync $600 http://eu.aoc.com/en/gaming/products/ag271qg
A fourth option was the Acer Predator XB271HU IPS 27" Display Port, 144Hz (2560x1440) NVIDIA G-SYNC, but it is $700