I had exactly the opppostie story:
First i had Corsair LPX 3000 on my X99 board, nothing but trouble, only one XMP profile. crashes.
I returned it and got Kingston HyperX Savage 3000, with 2 XMP profiles (2666 and 3000), and it instantly clicked and worked. Then bios 2001 came out and I could clock stable even higher!
Overall I get better (easier) stability and better benchmarks with RAM at 2666 (14-14-14-36)