I have used the Victorinox sharpener 7.8715 for three years with good result. It is a type I call a fast sharpener. To be dragged or pulled along the edge.
I will talk some on this type of sharpener and my impressions. The inserts are made of cemented carbide and it can be used on a wavy, plain or chisel edge. It can be used on the 84mm and up as well as the kitchen knives.
It is important when using this tool to have a medium pressure and to pull straight and steady.
If you use much pressure down upon an edge then it will or may shave off to
much metal and if you do not have a steady pull then one may fold or get an edge that will be uneven. When strong pressure or force upon the edge then it may get damages and remember that the pressure will be between the inserts and the edge on a very small
surface. This may damage an edge and actually fold the metal. Much pressure will or may result in shaving off metal at only one side.
That may sound negative but actually if you use light to medium
pressure and use a steady motion then it will perform very well and be useful. Most people never use a sharpening stone or a rod so with some small practice the 7.8715 will be well. After you get the edge that is sharp then use it again with very light pressure
some times to smooth the edge some. It is usually very difficult to get a perfect edge with this type of sharpener and by this I mean if you rub the finger nail along both sides then it is very normal to find a small irregular edge. This can be removed by
using the light pressure like I explained but it will usually never be perfect. Then it is the part with a SAK blade that is not even because of the design. This irregular line will also come on straight blades and the wavy edge on a kitchen knife.
There is absolutely nothing wrong with the quality on the Victorinox sharpener, it is well made and with good components that is durable. I have used it on many knives. I have two them + I had much practice
with the Accusharp type that is many years old. I have rotated the inserts in the Accusharp after many years of use.
The Victorinox sharpener is good! I always recommend for people to learn how to
use a water stone or a diamond stone or rod. What can be done after using the 7.8715 is to use a round diamond rod with light pressure two times on the edge to remove burr and the irregular line.
would recommend using the 7.8715 just from time to time and not all the time because of the folding problem with the edge. On the Swiss Army knives it must be used with extra care.
Then a very important
part! Remember to clean the area around the inserts with a brush and water.
Oil and dirt will or may result in an uneven edge and or maybe it will only shave off metal at one side.