The price may still sting a bit but honestly, it is only about a small premium over many 16GB DDR3 kits so the pricing on DDR4 is getting much better.  G.Skill's 16GB DDR4-2666 quad channel kit has timings of 15-15-15-35 and are fully XMP compliant so getting them out of the clamshell packaging may be the hardest step in installing them.  Of course many readers here, just like at Bjorn3D, are not going to be satisfied with the default settings which brings us to the overclocking results.  3048MHz @ 16-16-16-37 was perfectly stable in their testing at 1.35V and for those who don't mind the long term effects of upping the voltage to 1.4V there is more headroom left. 

"G.Skill has been churning out enthusiast memory that overclocks like nothing else we’ve ever seen. Pop a set of Ripjaws 4 into your dream machine and settle into the BIOS for an overclocking experience like you’ve never had!"

Here are some more Memory articles from around the web:

Memory