This morning I shoved a feather blade into my Muhle R89 Twist, I've had them for ages but was never quite brave enough to put one in my Dark Stag folding Kamisori. I could barely feel the blade as it scythed through 2/12 days coarse growth! Three passes and bbs finish, even my problem under jawline area was no bother. Barely a sign of irritation anywhere! Very impressive. I've decided that I really do need a sharp blade with my whiskers! This is staying in the razor until it's blunt!