Which Gaming PC Build?

I am building a gaming PC with the new GTX 1080. I'm considering two builds. The main difference between them is that one has a G-Sync monitor while the other is IPS. I used the saved money from the cheaper build with the IPS panel to upgrade various parts of that build. Which build would you recommend? And will the new Fast Sync help out much? Thanks!

PCPartPicker part list: http://pcpartpicker.com/p/BJJ3cf
Price breakdown by merchant: http://pcpartpicker.com/p/BJJ3cf/by_merchant/

CPU: Intel Core i5-6600K 3.5GHz Quad-Core Processor ($233.99 @ SuperBiiz)
CPU Cooler: Corsair H100i v2 70.7 CFM Liquid CPU Cooler ($98.00 @ Newegg)
Motherboard: MSI Z170 Krait Gaming ATX LGA1151 Motherboard ($161.19 @ Amazon)
Memory: Corsair Vengeance LPX 16GB (2 x 8GB) DDR4-2666 Memory ($64.99 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($84.97 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($46.98 @ OutletPC)
Case: Fractal Design Define S w/Window ATX Mid Tower Case ($69.99 @ NCIX US)
Power Supply: EVGA 750W 80+ Gold Certified Fully-Modular ATX Power Supply ($84.99 @ NCIX US)
Case Fan: Corsair Air Series AF120 Quiet Edition (2-Pack) 39.9 CFM 120mm Fans ($25.88 @ OutletPC)
Case Fan: Corsair Air Series AF120 Quiet Edition (2-Pack) 39.9 CFM 120mm Fans ($25.88 @ OutletPC)
Monitor: Acer H257HU SMIDPX 60Hz 25.0" Monitor ($347.99 @ Newegg)
Keyboard: Razer BlackWidow Ultimate Stealth Wired Gaming Keyboard (Purchased For $89.99)
Mouse: Logitech G303 Daedalus Apex Wired Optical Mouse (Purchased For $49.99)
Headphones: Kingston HyperX Cloud II 7.1 Channel Headset ($90.99 @ NCIX US)
Other: Windows 10 ($27.99)
Other: Extended Mouse Pad ($11.99)
Other: GTX 1080 ($600.00)
Other: Anti-Static Wrist Strap ($1.96)
Other: PC LEDs ($12.99)
Other: More PC LEDs ($12.99)
Total: $2131.74
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-05-17 18:11 EDT-0400



PCPartPicker part list: http://pcpartpicker.com/p/swWQ3C
Price breakdown by merchant: http://pcpartpicker.com/p/swWQ3C/by_merchant/

CPU: Intel Core i5-6600K 3.5GHz Quad-Core Processor ($233.99 @ SuperBiiz)
CPU Cooler: CRYORIG H5 Ultimate 76.0 CFM CPU Cooler ($56.60 @ Amazon)
Motherboard: Asus Z170-A ATX LGA1151 Motherboard ($150.99 @ SuperBiiz)
Memory: Corsair Vengeance LPX 16GB (2 x 8GB) DDR4-2666 Memory ($59.89 @ OutletPC)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($84.97 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($46.98 @ OutletPC)
Case: Fractal Design Define S w/Window ATX Mid Tower Case ($69.99 @ NCIX US)
Power Supply: EVGA 750W 80+ Gold Certified Fully-Modular ATX Power Supply ($84.99 @ NCIX US)
Case Fan: Corsair Air Series AF120 Quiet Edition (2-Pack) 39.9 CFM 120mm Fans ($25.88 @ OutletPC)
Monitor: Dell S2716DG 144Hz 27.0" Monitor ($533.99 @ Amazon)
Keyboard: Razer BlackWidow Ultimate Stealth Wired Gaming Keyboard (Purchased For $89.99)
Mouse: Logitech G303 Daedalus Apex Wired Optical Mouse (Purchased For $49.99)
Other: Windows 10 ($27.99)
Other: Extended Mouse Pad ($11.99)
Other: GTX 1080 ($600.00)
Other: PC LEDs ($12.99)
Other: Anti-Static Wrist Strap ($1.96)
Other: More PC LEDs ($12.99)
Total: $2156.17
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-05-17 18:12 EDT-0400