Some are too coarse and/or blunt for shaving. Haven't tried asr but tried some unbranded ones and they were blunt and scraped. The gem ones are coated although I think even they say 'for industrial use'.
Don't use the cheaper blades on ebay, they are not good enough for shaving, they tug and will need more passes and will leave you sore...i know from experience !!!!! :blush::blush::icon_sad:
Those Feather blades work very well in the Valet razors as the notches coincide with the shaving head. To use a Gem you have to remove the spine and then "clip" a bit of the back end of the blade off.
Gem s from Connaughts are the only blades I use, shaving full time with an O/C Gem Micromatic. I sold all my DEs after I found this combination, over eight months ago.
Regards,
Pete