In my 1940s GEM Junior these blades worked astonishingly well. BBS after 2 passes, and cuts with zero effort. I can hear the blade "singing" as I cut but can feel nothing other than the weight of the razor. The price is a little steep, but since essentially all SE blades in this packaging are the same there are definitely deals to be had.
My Gem blades are the 'Blue' variety. I am not certain whether mine are the same as in this article because mine have developed some rust spots despite my having washed the razor and blade in alcohol after each shave.
The blades are very sharp, but not as sharp as a Feather DE. They give me an easy, extremely close, irritation free shave with three passes.
I recommend these blades and the Gem razor to all and most especially to those who are blighted as I am with an especially tough beard.
These blades work for me better than the carbon steel type. They are smooth and give a BBS with no drama. Additionally, they do not rust as the carbon steel blades require drying after use. Also, the Gem SS are locally available.