I like the anhydrous, because it's cheaper, cleaner, more stable and more concentrated than liquid. I also like the idea of having the N placed deep in moist soil under the residue (this is ridge till). There probably is a benefit just running a knife down between the rows. If my tractor was an MX285 instead of an MX 210 I could pull 13 knives instead of 7. I do side dress 32% on headlands and other odd shaped fields.

I won't make any wild claims about yield increases from cultivation. But, I do believe there is a benefit from stirring the soil 3-4" deep mixing the weeds and residue stimulating microbial action and releasing nutrients. The corn in the headlands which is not cultivated never seems to yield as well, but there are other factors more likely the cause of lower yields in the headlands.