After reading 1usmus's Ryzen RAM OC guide I found out that G.Skill's 3600MHz CL19 stuff is pretty good and is equipped with Hynix C-die. They're pretty cheap because they don't have the more popular Samsung B-die, but they overclock like a champ! 1usmus got his kit to 3933 CL16. I followed the Ryzen DRAM calculator settings and am now running mine at a conservative 3600 CL16 @1.39V, more or less equivalent to B-die performance for about half the price.
My RAM timings below:
TestMem05 pass:
Feels a bit cheaty to use the Ryzen DRAM calculator to determine a Coffee Lake memory overclock though lol