$868 with a GTX1070 included is actually a damned good deal considering that the card itself runs a little North of $400 on its own. Personally I'm running 2 GTX970s because I'm pushing 4K, but thinking of upgrading to a 1080 because SLI has been a major issue.
The only upsides of the system I posted versus this one is that the ASUS comes pre-aasembled with Win 10 installed, double the RAM and a 1TB drive. The SSD is nice to have, but I prefer to use those only as system drives and have standard HDDs for the games due to the size of the games as well as reducing the amount of writes to the SSD which prolongs their lifespan.