I hope to have a review sample of this SSD in the not to distant future.
Regarding power consumption. I noticed a trend when I conducted the power testing article, that the more grunt an SSD had, the more power it consumed. This is pretty much as expected. To generate 300K IOPS requires a fair amount of processing power from the SSD controller. which generally means it will consume more power.
I also predicted in the article that once 'the real' consumer grade NVMe SSDs appeared they were likely to have lower power requirements than the mega powerful Intel 750 and the OCZ REVODrive 350. If these figures from Samsung for the 950 PRO are accurate, and I have no reason to doubt that they are not. Then the power requirements are indeed lower when compared to the Intel and OCZ drives.
There is also likely to be an 950 EVO version later, which I'd expect to have even lower power requirements than the 950 PRO.
One thing seems sure. PCIe NVMe SSD's are about to become very popular for consumers, and they are almost certainly going to be much faster than any SATA SSD.