Having used the cocking lever to hold the camera in my hand when not in use for years, I was happy to find out the R-D1 still had a cocking lever. Holding a camera without one (like my Eos 300D or any P&S) simply doesn't invite me carrying it ready-to-shoot in my hand.
So, don't throw away your thumb. Throw away that M8. Throw it my way, if you will.