@Chris_Rees APA102 (and SK9822) is still considerably faster than WS281x (SK68xx). Running APA102 at just 2MHz gets you almost double (1.875x) the pixel output speed of the fixed 800kHz WS2812 protocol. Anything above that is a bonus – especially if you can’t parallelise your output – not to mention the lower power consumption of APA modules (40mA compared to 60mA)
@Luminous_Elements no doubt they are fast. Another friend of mine had had great success with them. I have other reasons I don’t use them at the moment mostly because of long runs and additional component(s) needed to run them. Sure NRZ signaling has its drawbacks and lacks high speed. I am sure at some point I will look into the 4 wire pixel format but for now I have much more to accomplish with ws281x etc.