This is an interesting topic. The founder of the German kitchen knife forum I am most active on, and a few other users there did very extensive testing of what produces the most long lasting edge. He is a cook by profession who cooks thousands of meals per week (he cooks at a school and at a hotel) which enables him to make extensive tests. In his experiments he focused on high alloyed steels like 1.2562, M390, HAP 40, Rex 121.
To make it short: a knife sharpened with jig (angle control) lasts longer than freehand. A jig which also has pressure control makes a significantly longer lasting edge than one without: on the finest stones you sharpen with very little pressure, barely touching the stone.
It is easy to make a hair whittling edge with a diamond leather strop but it will not last as long, according to their tests.
The longest lasting edge is produced by going up to a very fine synthetic stone, either a Shapton 30K or a Gokumyo 20K (they are both 0.5 micron). And then finishing on a very fine natural stone (usually a fine Thuringian, a Japanese Nakayama (or similar), or an Arkansas). There has been a lot of discussion about why a natural stone makes such a difference with lots of theories but no clear answer. It just seems to work.
The jig most of the users of this forum use is called "Bogdan" named after the Ukrainian who developed it. It allows sharpening with bench sized water stones which is more useful when sharpening large kitchen knives. The one with pressure control has a spring at the top, there is also a "light" version without that feature.
Here are a few videos showing the Bogdan:
This one is the smaller standard version and here you can see the spring at the top:
(It seem to me that he is using too much pressure on the finishing stones in this video.)
I know that this can be a controversial topic and everyone has their own idea (not trying to convince anybody) but I thought it might be interesting to some as food for thought.
Also, the needs of a kitchen knife might be different than that of a hard use blade, some more testing would have to be done. But I can imagine that they are not as far from each other as the razor blade is from them.
