There is not enough of a noteable difference that the average user will be able to tell it honestly, even though they manufacturers would like you to believe othewise.
Factor in the very minor differences from one steel to another, along with the variability in the manfacturing process for steel, and the generation of the process is very unlikely to be the determining factor between the apparently-analog steels. The other factors are much more likely to make a difference, especially since most companies make minor little changes to the compostition of the steels they are mimicking. For example, D2 and Sleipner are similar, but the compostiiton of the two is actually chemically different. M390 and CPM20CV are closer, but they are still chemically slightly different. N690 and 440C are actually pretty different from one another in terms of composition, even though N690 was intended to be an improvement on 440C originally, so you get the idea that the steels aren't going to ever be true analogs of one-another.
The other big thing to take into account is that small variables in the heat treat, shaping, and design of the knife, even if 2 knives are "identical" will likely have way more actual effect on the attributes that we are able to actually feel and differentiate from one another than the generation of the powdered process.
So basically, it might make a small, minute difference, but there are way too many other factors to try and say that the generation of powder metalurgy used is going to be the determining variable, and the natural variability of all of the steps in manufacturing steel and then turning that steel into a blade to use will likely completely hide any differences there might be between the steels based solely on the generation of the process used.
It's not like comparing ingot steel to powdered steel, where the difference in structure is going to be significant enought that you can see the difference between the two pretty easily.
