The many faces of Chad :
Being able to push shave at a high polish, or taking a course finish with a rough stone is an attribute of any steel.
Several of the steels the Japanese use don't take well to very coarse edges mainly as they are *very* brittle and the edges tend to fracture instead of getting cleanly cut. Even if a coarse edge is applied, they are not overly functional with it because the microserrations break off too rapidly. This is why natural waterstones are prized by the master japanese craftsmen as they are softer and "flaky" and thus can produce finer edges. Note that their sharpening tolerance is very extreme, far beyond simple shaving.
On the opposite side, very soft steels don't respond well to high polishes as they develop burrs very easily and again even if a quality high polish is obtained, it isn't functional as it will bend far too readily. These steels tend to work best with a slightly more coarse finish. With large microteeth, the edge can continue to cut well even if slightly deformed as there is more overlap between the cut path of the individual teeth. At a basic level, the larger the teeth the directly larger they can be deformed and still be well enough aligned to continue cutting.
Of course it depends as well as what is being done, it might be that the task is so edge specific you would go with a less than optimal edge anyway and thus put a coarse edge on a really brittle steel (but in some cases, see below, the limitations can be so severe that this isn't possible). But steel can have an influence both on the ability to take an edge of either type, and how functional it will be in use.
Aside from steels, and moving on to blade materials in general, Titanium and Ceramics are two which respond very poorly to coarse edges. Titanium tends to oxidize and smooth out micro-serrations and Ceramics tend to just break apart. With Missions Ti I even went to using very coarse belts (100 AO) and even bastard files and could not gain any increase in slicing aggression or edge retention. In general you were better off giving it a higher polish regardless of the type of cutting. See the review for more details.
Cutting performance is an attribute of geometry, not steel type. Steel type will effect wear resistance, impact resistance (though so will geometry to a much greater extent), corrosion resistance, etc.
Chad, it is bad enough that you are quoting an arguement I had made as if you presented it [as an arguement to me which is really kind of odd] at the very least get the details correct. Here is an example of how you do it correctly :
http://www.bladeforums.com/forums/showthread.php?s=&threadid=175966
Note this thread is over two years old. It was also not the first time that I made such edge modifications so quite frankly I don't need you to tell me how geometry influences cutting performance, especially when you can't even get it correct when I layed it out for you years ago.
Here is a quote, from me, from that thread :
"... the steel and heat treatment make no effect at all on the cutting ability of a particular geometry (*minor* effect on surface friction only) and only a very small effect in regards to edge finish and to see the latter you have to be working at very fine polishes (below the grain size of the steel) and at very acute angles. "
The critical part is "of a particular geometry". With some steels specific geometries may not be obtainable [consider time, abrasive requirements or steel properties as mentioned in the above] or functional at those geometries as they can be with other steels.
In the *years* since I made that statement I have found a few exceptions to the "very small effect", so I would change it slightly to :
"Cutting ability in general is mainly controlled by geometry and is little influenced by steel or heat treatment. The material properties of the steel influce mainly how functional the blade will be at that geometry, specifically does it have enough strength, toughness and wear resistance to hold that geometry without suffering excessive deformation, fracture or wear [or corrosion].
There are a few exceptions to this general rule, as always. Some steels may be so brittle that they do not respond well to coarse edges, neither taking them well, or being very functional in use as the teeth snap off readily. other blade materials may suffer related problems with high polishes, being difficult to apply due to lack of stiffness which also leads to very quick blunting.
In extremes, if the users tolerance to sharpness is *very* high, differences can also be noted among the various steels in ability to take various finishes. It takes very extreme viewpoints to notice such behavior however, and for most such disparity is not a factor. For more information check posts by Jeff Clark on the "sharpness" and sharpenability of various steels."
There are also further complications as to how steel can influence cutting ability at a particular geometry, specifically how the steel breaks down in use, for example see :
http://www.bladeforums.com/forums/showthread.php?s=&threadid=226263
This was a year ago Chad, try to keep up.
-Cliff
