I've used both SATA + NVME SSD
The difference between both is negligible as not a lot of apps / games can utilize NVME

Windows 10 Cold Boot Time (Fast Boot Enabled)
Single HyperX SAVAGE 240GB : 9 seconds
Dual HyperX SAVAGE 240GB RAID 0 : 15 seconds
Samsung 950 PRO 512GB : 3 seconds (I kid you not)

But it all comes down to your pocket
If you can afford NVME, go for it
If you think an NVME SSD is too expensive, then go for SATA SSD

Thanks guy. I finally bought my new system;

i7 6700 with Hyper 212X
Gigabyte Gaming 3 - I was thinking of Gaming 7 for its HDMI 2.0. But later gave up as I thought just matter of time I will get a graphic card that has HDMI 2.0.
32GB RAM - Should be sufficient for now
Samsung 950 Pro 256GB - Really fast man... No jokes. I learn that not all SSD are built the same
Window 10.1

So far so good. Whole system damn silent... I can hardly tell if it is on.