IMO, they are pretty much equal more or less at those settings. The fast CL balances out the speed bump of 2666. But it's very close. TJ Hooker made a good point. If the ram was in a Ryzen system, you will get more out faster speeds. If it's Intel based, not half as much.
Also, keep in mind OC'ing ram can be fruitless. Most generic DIMMS have little room to move . But it can be done with patience and testing. I've my generic Crucial 2400mhz running at 2733, with CL20 and pretty much all other timings at the rated jedec settings, with only a 1.25v on the mem.
If for Ryzen, faster ram really helps. Going from 2400 to 2933 or above can yield 10-20% performance increase for games (game dependent), beyond 3000mhz the effects of faster ram taper off quickly. The difference between 3000mhz ram and 3200mhz or faster is only just 1-2%
I'd add, that faster ram helps Ryzen, but is almost essential for a 2200g/2400g, and doubly so if using on-board Vega. Min id be looking at is 3000mhz. You board supports speeds up to 3200mhz. If i were you and you were sticking with on-board Vega, I'd go even further than $20 dollars to get the best performance I could out of the integrated GPU.