A:AnswerFreesync vs Gsync. This monitor uses Freesync which is open-source tech. The S2716DGR uses Nvidia proprietary Gsync tech. A rule of thumb is AMD gpu = freesync, Nvidia gpu = Gsync.
A:AnswerXbox one X has a maximum refresh rate of 120hz when using either 1080p or 1440p, and this is only achievable over HDMI 2.0. The tricky thing is to get the monitor calibrated to 120hz for the Xbox to recognize it as an option. I don't personally use this monitor for xbox. The Samsung CHG70 is a guaranteed success for xbox one x at 1440p 120hz.
A:AnswerI play Apex just fine on this monitor. I would check what settings you have on the monitor and advise you not to use the super fast mode as that's where I noticed screen tearing. Its hard to say it's a monitor issue without knowing the Specs of your rig.
A:AnswerYes anything with a first number of 2560 whether it be 2560x1440 or 2560x1080 the 2560 is the width in pixels and the 1440 is the height in pixels.