It's another of those highly caveated "whatever works," things.
To some extent the knife profile will impose itself on the balance between push cut, the classicly French silent guillotine and slide, and/or rock cut. A "German" profile favors rock cutting -- if for no other reason than because it will "accordion" (not quite all the way through the last part of the cut), if it isn't rocked -- which creates the characteristic pumping action. A flatter profile as with a nakiri, or Hung's trenchelard slicer, favors push cutting.
Cooks from my generation who learned to cook in "classic" kitchens learned to go through the block, plank, stick and dice sequence by starting each cut with the tip down -- but not necessarily touching on the board; then bringing the handle down while sliding the knife forward (not "drawing it") in order to both finish the cut with the flat of the knife edge (a French profile is pretty flat from about the middle of the edge to the heel), and to keep the cut quiet. No tap-tap-tapping for us. We learned that good cooks did not make noise with their knives, whisks or other tools. It's not particularly true, but that's how we learned.
Of course, to some extent you impose your style your on the knife too. But the profile plays a sufficently strong role that it only makes sense to choose a knife that will work with your style, or one which will favor a style you want to learn. For instance I'm looking for a knife which will be very different from current go-to Sabatier in almost every way other than the shape of the knife along the edge -- because as much as I want something different, I don't want to relearn basic skills.
Speed cutting pretty much requires making noise. You can use a flatter profile and lift it straight up and down, or you can use the bellied tip of a chef's knife or slicer and use a slightly elevated wrist as a fulcrum and flick the point down so the belly hits the board square. Because it negatively impacts most cooks' quality and consistency speed cutting is pretty much just show off stuff. There are a few guys with the talent, who put in the time, and became sufficiently solid to make it productive, but not many. They're better than the rest of us. For sure. Did I mention the noise?
You see something a lot like speed chopping with tip work done at regular speeds as well -- for instance when pros score onions and shallots, etc.
It's either that or bringing the blade down onto the board, and lifting the handle so the tip cuts all the way down. I.e., pumping. This second way requires enough pumping to make it annoying under the best of circumstances, and still more of a PITA when using knives with German profiles or with knives with high tips. (Shun Classic Chef's have both -- which is one of the reasons so many people don't like them.) A lot of Japanese gyutos, Masamoto for instance, use a slightly dropped tip which makes a lot of things easier.
As a professional you have to balance quality, consistency and speed; how you do it isn't important. As a home cook, it's all about quality. Either way you don't get graded on technique. Technique's sole purpose is to serve results. Form ever follows function, that is the law.
If you have great hand-eye coordination and are talented enough to make anything work (like Hung), it doesn't matter. Similarly if you can't keep your knife sharp it doesn't matter or your board sufficiently organized to use the knife without cutting into piles of already cut food it doesn't matter very much either. It doesn't take much awareness to realize that at least a gazillion great meals have been prepared with each of the three broad styles we're talking about here -- not to mention their variants.
For someone who wants to learn or improve, I favor a compromise between classic French and push cutting. It's relatively easy to learn and better suited to the normative western cuts; and also suited to chef's/gyutos (which are so productive for so many other things) than pure push cutting. It better suits the French profile of French carbons and Japanese gyutos which have better blades than their German styled counterparts, nor does it require all that handle pumping.
But to each her own.
Edited by boar_d_laze - 8/25/10 at 3:09pm