Feather, from Japan, is considered to be by far the sharpest blade. That is exactly why so many people are so fond of this blade; it leaves no stubble unshaven. But to others it is simply way "too sharp", so they prefer the slightly milder variants. The blade Astra is recommended as a little less sharp type. The Personna Platinum or Personna Red, as the blade is called due to its red packaging in some countries, and the MÜHLE blade are at a similar level. Even though the last three blade types are quite close to each other with regard to their various degrees of sharpness, there are slight gradations - and who has decided on a model will rarely deviate from it in the future.