after using a Merkur HD for a while now i decided to use an Atra cart that still had a few shaves in it. i couldnt hardly feel the razor on my face (like it was numb) till i went ATG on my neck. i guess my skin toughened up. when i used my old SS then used carts i could feel the cart cutting. i guess the HD's blade gap must have scrapped more skin off and thickened it up a bit. weird?