I would say they are worth the money. Go for it. I took a blunted Pampered Chef kitchen knife from completely dull to razor sharp in about an hour (of bumbling and repairing mistakes LOL) heavy grinding. If you have a severely damaged blade, grab one of those cheesey two sided stones from Harbor Freight to do your heavy grinding. From there these stones will work very well.
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.
You need to adjust your fingers as you move the knife back and forth. Because sharpening takes place under your fingers, start with them at the tip and, as you pull the knife back toward you, release pressure completely and pause. Then, shift your fingers just a little down the blade toward the heel. This finger dance is critical and takes time getting used to.
For instance, American Novaculite (aka Washita and Arkansas Stones) is a form of metamorphic Chert that produces some of the best known and best loved natural whetstones in existence. Then, there is a form of Belgian Coticule which has been known for providing extra-keen edges since Roman times and, there is a Japanese Siliciclastic sedimentary stone (aka Japanese Water Stones) which consist of a fine silicate particles suspended in a clay matrix. Plus, there are also various types of man-made whetstones available such as Silicon Carbide (aka Crystalon) stones and Aluminum Oxide (aka India Stones) as well as a synthetic Corundum (aka Ruby) rod and Aluminum Oxide impregnated ceramic rods as well as several different types of diamond hones.

I purchased this set together with the 400/1000 grit stone assuming that some of my knives were quite dull and would need work on a coarse grit stone. Premium Whetstone Sharpening Stone 2 Side Grit 400/1000 | Knife Sharpener Waterstone with NonSlip Rubber Base & Flattening Stone. This is my first wetstone. First off I tried to sharpen my Chicago Cutlery boning knife. This knife is nearly thirty years old, has been abused in may ways and was quite dull. It was very difficult for me to get a burr on this blade, which I attribute to poor technique. Next I moved on to my Henckels Professional S paring and chef's knives. The paring knife was moderately sharp and was modestly improved after working over all three grits of stone. It would cut paper but again it was difficult to develop a burr with this blade. Undaunted I switched to the chef's knife. This knife is twenty years old and has never been professionally re-sharpened. I have sharpened it twice with a Lanksey sharpening system which marred the finish but did put a good edge on the blade. Lansky Standard Coarse Sharpening System with Fine Hones. The chef's knife was moderately dull and had several pits visible on the cutting surface. I modified my technique for passing the knife over the stone and worked the chef's knife over the 400 grit stone aggressively and eventually I was able to get a burr to form from the tip of the knife all the way to the handle. From there it was a simple process of reforming the burr on the 1000 grit stone and then finishing on the 6000. After sharpening, the chef's knife easily and cleanly slices a tomato with very light pressure and is in my opinion very sharp. Not sushi knife sharp but more than enough for the chopping and slicing I expect of it. I'm looking forward to going back and working both the boning knife and the paring knife over again. Don't expect a good result from this product the first time you use it. Watch videos on using a wetstone, expect to spend at least twenty minutes per knife at first, and practice forming a burr. If you can form a burr, you will be able to successfully sharpen your knife.
As opposed to water whetstones that require you to pre-soak the stone, the Norton oil stone is pre-filled with oil to save time and eliminate the need to pre-soak it prior to use and the lubricant stays on the surface during sharpening.  The oil also prevents metal from bonding with the abrasive surface by flushing away dislodged abrasive and metal chips.

Now move the blade – with a little pressure – in regular movements up and down along the sharpening stone. Always maintain the angle between the blade and stone. You will notice a burr become visible after five or so movements. Mentally divide the blade into three sections if the knife has a large blade. Always start with the tip and work back towards the bolster.
The Sharpening and Specialty lines of waterstones from Naniwa are available in several packages of three to five stones. The Specialty line is the same as the Sharpening line, but half the thickness and therefore less expensive. Both the Sharpening and the Specialty stones are 8 1/4" long by 2 3/4" wide, amply sized for most knives and tools. These are a higher grade stone that do not require soaking before use. While you would need a flattening stone in addition, these kits are a good way to enter into premium grade waterstones.
Fortunately our product review experts have put their noses to the grindstone (so to speak) for you and come up with a comprehensive list of the 14 best knife sharpeners on the market today. They’ve cast a wide net that includes everything from the most elaborate mechanical devices to the simplest sharpening sticks and stones so you’re bound to find one that fits your needs, temperament and budget. Keep in mind that any opinions expressed here are those of our experts.
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.