From what I gather your saying it would be beneficial on mid range solutions like a 1920x1080p 60hz monitor correct? Well that being said most mid and high end GPU's are getting to the point stability at 60hz on a 1080p screen is a snap for them. Those GPU's normally sell aroudn the price point of 300 bucks which is about the premium you pay for a monitor with Gsync (I think 250 may have been the lowest I saw) which would beg the question as to why you didn't just invest in the higher card to begin with since you would probably be paying around 450-550 bucks for the monitor alone. Would it make a difference though, yes it would but not until the price comes down on the modules to make it more manageable at the lower price points. I see Gsyncs uses at higher resolutions and especially great at the high refresh monitors where stability is difficult which includes the low range if you can not keep the FPS stable. But I still stand by saying that you might as well just invest that money into a better video card at that point.
Personally, I just skipped it all and went for the next step up beyond 1440p.
@bc.be4ts If you want a Gsync monitor, I could suggest a few as well but I personally have only seen one in action so far.