It's not even about wining the specs war, it comes to a point when your base model just isn't powerful enough and can't push enough pixels to show the next gen effects or 4k assets on a 4k tv which will be what the mainstream using comes 2020. Come on guys by the end of 2020 no one and their grandma would want anything to do with a 1080p set
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I'm sure devs could implement a RT mode at the sacrifice of res or fps etc, it shouldn't come in the way of other things. But man there's a world of difference of designing a game with 6-7tf of power vs 12tf, one system would have enough juice to make a world twice as big for example. Yet the more powerful SKU X2 could only up res the smaller world in 4k, higher textures and af.
Price is indeed a big factor, I wonder how much a 15tf X2 would cost, $599 sounds likely.