About two months ago I bought a Ducky One TKL RGB with RGB blacks. These are much smoother than the other blacks I have here. They also feel just a bit lighter. I'm sure the specs say the RGB & regular blacks are the same force, so I guess the smoothness makes them feel lighter also.
I have a Ducky G2 Pro PBT with blacks (had that one at least four years), a TG3 with blacks, and I don't have anymore: another TG3 with blacks and a Cherry board with blacks (got that one used so I don't know how much use it had seen before I bought it. Had very smooth blacks, tho). The RGB blacks in my Ducky One feel like none of the others. They feel like a different switch.