Heres why I wasn't impressed at first. I only used it for a few minutes on each side, which resulted in nothing. I watched a video online with a master chef using his stone, and he sharpened his knife for 10 minutes on each stone before moving up to a finer grit. I took this hint, and used sharpened my knife on each side of this stone for 10 minutes, which led to perfection.
The goal when sharpening is to create a burr, which is a tiny whisper of metal left on one side of the blade. You'll know you have a burr when you can feel one smooth and one scratchy side to the edge. Warner's is formed in no time at all; I struggled. Nevertheless, eventually I got there. Once you've got the burr, it's time to move on to step three.
The composition of the stone affects the sharpness of the blade (a finer grain, usually, though not always, produces sharper blades), as does the composition of the blade (some metals take and keep an edge better than others). For example, Western kitchen knives are usually made of softer steel and take an edge angle of 20–22°, while East Asian kitchen knives are traditionally of harder steel and take an edge angle of 15–18°. The Western-style kitchen knives are generally in the range of 52–58 on the Rockwell scale, which denotes the relative hardness of a material.
Historically, there are three broad grades of Japanese sharpening stones: the ara-to, or "rough stone", the naka-to or "middle/medium stone" and the shiage-to or "finishing stone". There is a fourth type of stone, the nagura, which is not used directly. Rather, it is used to form a cutting slurry on the shiage-to, which is often too hard to create the necessary slurry. Converting these names to absolute grit size is difficult as the classes are broad and natural stones have no inherent "grit number". As an indication, ara-to is probably (using a non-Japanese system of grading grit size) 500–1000 grit. The naka-to is probably 3000–5000 grit and the shiage-to is likely 7000–10000 grit. Current synthetic grit values range from extremely coarse, such as 120 grit, through extremely fine, such as 30,000 grit (less than half a micrometer abrasive particle size).
I've always wanted to sharpen knives on water stones, and this set gave me the motivation to finally give it a shot. The price is amazing for the quality and content of the set. It comes with all the grits you need to sharpen anything... I usually start on the 400 grit if the knife is very dull, or directly on the 1000 grit if it's not too dull. The 3000 and 8000 grit stones are softer and ideal after the coarser stones. The online learning section is truly amazing, much better than I expected. A convenient place with instructional videos and many articles about knife sharpening. Only downside is that the knives are now so sharp I need to be very careful using them... but that's a good thing! I feel like I fell in love with knife sharpening again.
Removing the burr is fairly simple. You'll need a leather strop or block (this sort of thing), which is designed to catch the metal fibres from the knife. You could do it with a fibrous tea towel or some newspaper if you like, but I'd suggest going with leather to begin with. The motion is fairly similar to sharpening. Draw the knife over the leather, going away from the edge at roughly the same angle as when you sharpened.