G-Sync is a luxury.
G-Sync is indeed very nice to have if you will actually use it for things like high-fps gaming, the visual effect is very subtle but it's noticeable enough that you'll no longer enjoy gaming on "cheap" monitors which lack it.
G-Sync is very expensive tech bloat (and a needless complex gizmo which can fail) if you won't ever run any software (games) which make use of it.
If you wanna game heavy then you won't regret buying $$$ G-Sync. Otherwise you'll probably be happier with a monitor that comes with larger panel size, larger resolution, or lower cost. I'm still not convinced 120Hz or 144Hz (or more) refresh is really needed, after all the human eye (at least my eye, lol) can only "see" about 30fps and motion displayed at 60fps (= 60Hz) looks smooth and flawless enough. I've also found that larger-sized high-resolution displays with "primitive" V-Sync will still put so many raw moving pixels in your face that you can afford to forego luxuries like G-Sync (or ultra graphic quality settings, 4K oversampling, etc) and still enjoy very immersive gaming environments - your brain (at least my brain, lol) "ignores" all the almost-invisible graphical artifacts while staying focussed on the good stuff. I prefer 28" WHQD 2560x1440 monitors, though I admit I've never gone larger simply because that's the biggest size I can fit on my desk.
There's still tons and tons of
uncertified and underspec DisplayPort cables on the market. "Uncertified" meaning they often bear a not-quite-right symbol and are not *properly* certified to meet official specs. I've heard of people getting junk DP cables in the same box as their new GPU cards, though I've never seen it myself. DisplayPort converters (DP-to-HDMI, USB-to-DP, etc) always degrade signal bandwidth, but pin-compatible DisplayPort adapters (like DP-to-miniDP, etc) do not. DisplayPort cables need to have high quality conductors and shielding to carry signal integrity, but many of the longer DP cables sadly just ain't that great. I think this rampant DP psuedo-certification/piracy has been "allowed" to continue for years only because DP isn't (yet) a standard on regulated devices like 4K televisions.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams
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