I'm not saying that there has never been a CRK with any thumbstud problem ... I said I must be very lucky I've never handle any that had any trouble opening. Several post they feel it's too hard to open ... so I would guess some must be. But just as some see a Hinderer XM-18 with a tight detent as a bad thing ... I much prefer that ... it allows for the blade to fire open as a flipper should. Everyone is different ... nothing malice in my post ... sorry if you took it as such.