A strong GPU paired with rather low end hardware is the problem of many prebuilds, this one is sadly not an exception. The price of $923 is also not that fantastic (if you add ~10% sales tax on top of it).
Problems are:
-A PSU that is theoretically strong enough, but going for 500-550W would be better.
-The i5 is running at a low clock speed and will bottleneck the GPU in CPU heavy title like GTA V, Witcher 3, Watch_Dogs 2 etc.
-They probably only use one stick of ram here, which isn't good performance wise.
-no USB 3.1 support
A RX 470 or GTX 1060/3G would be a better fitting and much cheaper graphics card because this system will run into performance problems anyway because of the CPU. The GTX 1070 won't be able to reach its full potential here.
If you're willing to spend 930-950$ (after taxes) than something like this will give you much better performance.
CPU: Intel - Core i5-6600 3.3GHz Quad-Core Processor ($211.69 @ SuperBiiz)
Motherboard: ASRock - H170A-X1/3.1 ATX LGA1151 Motherboard ($83.89 @ SuperBiiz)
Memory: Crucial - 16GB (2 x 8GB) DDR4-2133 Memory ($103.99 @ Newegg)
Storage: Kingston - SSDNow V300 Series 120GB 2.5" Solid State Drive ($54.88 @ OutletPC)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.33 @ OutletPC)
Video Card: Zotac - GeForce GTX 1070 8GB Mini Video Card ($334.99 @ Amazon)
Case: Thermaltake - Versa H21 ATX Mid Tower Case ($36.89 @ OutletPC)
Power Supply: EVGA - 500W 80+ Bronze Certified ATX Power Supply ($36.99 @ SuperBiiz)
Wireless Network Adapter: Gigabyte - GC-WB867D-I PCI-Express x1 802.11a/b/g/n/ac Wi-Fi Adapter ($29.99 @ SuperBiiz)
Total: $941.64
Prices include shipping, taxes, and discounts when available
PCPartPicker part list:
https://pcpartpicker.com/list/pVFfgL
It has all the pros of the prebuild like 120GB SSD + 1TB HDD, WiFi, Bluetooth 4.0 and a GTX 1070, while improving the negatives.
The CPU is much faster, the PSU won't let you down in a year or two, it has two times the ram in dual slot configuration and USB 3.1 support on the front and on the back. 1080p/60 at reasonable ultra settings would be possible on this machine.
Possible upgrade paths for this build are: Stronger GPU, more SSDs, more RAM and a better CPU up to the i7 7700 (the newest asrock 7.20 bios seems to support kabylake CPUs on h170 boards).