Like Bennyprofane already posted, i`am a freehand honer for about 15 years, and i think i am quite good at it. For about 10 years ago i started razor honing too. I always searched for the perfect edge, bought many, many stones (especially natural ones....) mostly razor finisher.
This was an important step to get knowledge about edges, what happens with the steel etc.
Especially microscope inspection of edges, even while handsharpening are an important step.
But i was not able to bring usefull edges with that ultra fine stones on my Gyutos....... Handsharpening is limited too about 5k Grit in my opinion, some Suita stones work as well, the mentioned bity edge....
The more stones in use the more failure is involved while freehanding....
After a big discussion in a german knife forum, mainly about perfect polished edges (the russian guy, on the search for the perfect edge in opposite direction (rope cutting.....), stated much about edge damage because of rough grind marks etc. I thought he was talking bull****.... finally i decided to give him a try on two of my knives (a Kato and a selfmade one).
The results totally shocked me... The blades came back razor sharp (HHT 5) on all over the blade, perfectly sharpened!
I was able to get such high sharpness by hand, but there was no toothyness left after a few cuts, even with my best knifes, so i thought, this could not be usefull.
But they both where at least 2 times better/ longer cutting then the same knifes with 5k Finish by hand. And this with feather blade sharpness.....
I recognized that my hansharpening ability is not good enough...
Well it was much better then lets say Yu Kurasaki`s, (meet him at an sharpening event in munich / DICTUM Shop last year.) And he may only be tired, who knows, but he don `t even touched the edges of the sharpened blades..... He only scrached my Kato badly..... .
So i get information from him (the russian guy), what its all about with edges, and he was totally right.
As i waited for the Bogdan Manko Skorpion, i decided to check all other sharpening systems around. I got some quite cheap, like the edge pro, edge pro clones, got the opportunity to test wicked edge, and the insanly expensive Magna Tec sharpener....
(just another Edge Pro Clone made with german quality, and so is the price......)
As mentioned before this jiig system `s can make a superb edge, but the retention suffers like freehanding.... Maybe you may reach 10% more edge retention but that`s it. So not everything is about angle. (Btw. you can hold the angle perfectly with Edge Pro/Clones......) There are other limitations like no really option to thin your blades etc.
Problems of handsharpening:
-The more stones in use the more failure occur.
-Nearly any handsharpener, don`t hit the very last edge (you can, using microscopes and much attention!)
-Most handsharpeners using abbrassiv loaded strops to get full potential of their action. This is in my opinion the main cause for bad geometry on knives...... The roundet edge has to set back while honing on stones again, therefor you need rougher stones, more steel is removed so teh geometry suffers, and thinning is necessary much more often.
Bogdan `s System keeps the angle for you, reduces the needed pressure (less burr, less stress for the steel).
They will get dull (this is no magic voodoo thing...) but the edge retention is simply much better, even with a finer finish. Imagine what i would be like if you can cut with a 20k Gokumyo finish in pro kitchen, with no issues......
The reduced pressure, may be known by the straight razor guys, the finish step had to be made with razors weight only, to get a good edge.... This is not possible while sharpening kitchen knives.... They are almost too heavy.
This is the key to a destressed edge, and what makes the edge retention so good. With a higher angle (36 degree on most of my knives, cause i mainly rock chop on plastic boards), depending on your cutting motion and used boards you can adjust your edges to the best possible results.
Btw, the knives had to be thin behind the edge, this is the most necessary thing, with a laser you will not feel much difference between 25 degree angle too 36 degree...... So no wedging at all.
With my Bogdan Skorpion (knifemaker model) i even can use it for thinning on my watercooled benchgrinder! (with control, so no failures any more.......