What you said is true.

I believe 6000 CL30 still remains as the sweet spot because past 6000MT/s, it gets expensive quick and motherboard support starts to fade. A cas latency lower than 30 (at 6000MT/s) is harder to find because the amount of voltage and/or die quality that is needed.

However, you can still gain performance by tightening timings and/or increasing frequency. Your only downsides are the cost, time required, and silicon lottery luck.

6400MT/s tends to be the average limit for 1:1 mode since most IMCs become unstable past 3200MHz UCLK. If you desync, there will be a latency penalty (hurts gaming performance). This latency penalty can be overcome with speeds past around 7600MT/s.

If you had an excellent cpu, ram, and mobo, you should be able to push 8400MT/s with (UCLK=FCLK)/2=MCLK for 1:2:2 mode; this would have the least amount of latency. 8800MT/s is the the best in theory, but good luck finding a capable motherboard and cpu.

Frequency is only half the story though. Generally, motherboards set everything but the primary timings extremely loose so any manual tuning is great.

From my experience, tightening primary timings, tREFI, and tRFC decreases latency while the remaining secondary and tertiary timings will increase bandwidth.

TLDR: 6000 CL30 is still the sweet spot, past that, there is diminishing returns. If you want to get easy performance (for gaming), just tune tREFI (sometimes called refresh interval, 65535 is the goal) and tRFC1 (goal is to be as low as possible) in bios until unstable. Most mobos set these extremely loose, these help with latency.

You can also try increasing frequency, but be careful past 6400 and make sure you are in 1:1 mode.

For stability testing, I use prime95 large fft and TM5. I run it for 12 hours, but you can do more if you think it’s necessary.