Ok guys, I did some rope cutting today on 5/8" hemp. I tested the Hap40 Delica against my Gayle Bradley Flipper in m4 (rc 62-63). I don't have calipers but I would put the edge on the Delica at slightly thicker than the GB. Probably .015" vs .018". Just a guess. Both were beveled to 30 degrees then micro beveled on a 1200 grit DMTs that are mounted to the Sharpmaker at 40 degrees. The edges on both would easily and firmly bite into my beard or the hair on the back of my head on contact.
In this test, I did groups of cutting. I also make multiple sawing motions (about 7) from the start even though its not necessary. The goal of this is to wear the edge as quickly as possible.
-The first set of cuts was 30 (x7) with each knife. At the end of 30 I could feel a definite difference in the two edges. The hap40 edge would still bite and stick in my beard hair but the m4 was starting to slip. The Hap40 would still easily do a straight (perpendicular) push cut into magazine paper where the m4 needed an to be angled to make the pushcut. Both would still easily shave arm hair in one pass.
-The next set was another 20 (x7) cuts. After this set I could feel a bit more degradation in both edges. Neither would stick in beard hair at this point. Hap40 would still push cut magazine paper at an angle but m4 needed just a bit of slice.
-Next set was another 20 cuts which put the knives at 70 (x7) total. After these, neither would pushcut magazine paper and both would occasionally show some VERY slight snagging when slicing the paper. Hap40 would still cleanly shave leg hair in one pass...m4 needed a couple of passes to shave clean. Two VERY TINY shiny spots appeared on the m4 edge. Nothing visible on the hap40.
-I made one final run of 30 cuts to bring them both up to 100 cuts. The interesting thing is the m4 seemed to actually catch up a tiny bit after this run. The hap40 had been notably winning up until the last run but after the last 30 they seemed to be closer. The hap40 still had a bit more bite but they were fairly close. Both needed a couple of passes to shave cleanly and both showed slight snagging when slicing magazine paper. The easiest way to tell the difference at the end of this run was the hap40 was still slicing the rope with less force than the m4. After the run, I tested and found that the hap40 would still fully slice the rope on a 2" draw where the m4 would not quite (under the same amount of force). The shiny spots on the m4 were still barely visible and there were still none visible on the hap40.
At that point, both edges were past what I consider acceptable sharpness so I didn't bother going any further. I have done this same testing with s30v (though in a thicker grind) and it took 50-60 cuts to dull to the point where these two were after 100.
Ok, it's kind of a haphazard way to test and report results but hopefully someone can extract something of value from it. All I can tell you is I continue to be quite happy with hap40.
The simple answer is there is no "best" steel. It all depends on what your requirements are. Luckily there are hundreds and hundreds (likely thousands) of threads on blade forums addressing your question so if you are looking to learn, you won't run out of study material for a long long time. 
