RAM choice - higher freq or lower latency?

[Wizeowel]

Is not an either/or.

CAS latency is measured in the number of clock cycles, so the latency is dependent on the frequency.

You can convert to nanoseconds to get absolute latency.
The F4-3600C16D-32GVKC kit has CAS latency 16 and frequency 1/3600, multiply to get 4.444 ns absolute latency.
The F4-3000C14D-32GVR kit has CAS latency 14 and frequency 1/3000, multiply to get 4.667 ns absolute latency.

So the F4-3600C16D-32GVKC is faster and more responsive.


Edit:
However, regarding the QVL, your AsR Z390 Phantom Gaming4 is listed on the G.Skill product page for the F4-3000C14D-32GVR (see https://www.gskill.com/qvl/165/184/1...C14D-32GVR-Qvl) but not for the F4-3600C16D-32GVKC.