How well do counter top knife sharpeners sharpen knives? Are counter top knife sharpeners like the IQ knife sharpener good for sharpening knives (or cheap knives)? I have used the IQ sharpener and it is still hard to cut through big onions. I would like to know if it's problem with my technique or the product category itself just sucks.
A pull-through sharpener will never do as thorough a job at sharpening your knife as a stone, and over time will lose its efficacy and actually dull your blade. In a pinch they can be useful, but be sure to give the knife a few passes on a good quality steel afterwards, as the pull-through sharpeners tend to remove metal quite coarsely.