The gap is 12600K between the 3200MHz CL16 and the 3600MHz CL18 memory.
The gap is 12600K between the 3200MHz CL16 and the 3600MHz CL18 memory.
I've moved up to 12600 K with DDR4 and have the same kits you mentioned. Switching to a 3600 MHz CL18 would likely improve performance, especially in demanding games.
Both sets offer comparable latency, so the 3600MHz model would simply provide a bit more bandwidth. There could be minor advantages in specific games, but overall the gain would be small and likely not justified by the price. If you have a dedicated GPU, performance differences from system RAM are probably negligible. With an integrated GPU, the impact is even less significant.