To each his/her own, of course. I agree that a faster lens is what you want if you want to freeze motion, but... ultimate sharpness is a rather tired concept in photography, in my honest opinion.
I'm not going to fall into, and I haven't pretended even, discussing whatever you (or me for this case) consider a desirable goal for any photographic work, that's mainly on the personal side. I'm pointing that there are technical facts that you can't avoid and makes a difference to someone used to shoot with the M; if you have to have a pin-sharp candid portrait under low light better get your tripod than bracing anything hoping to nail it... given those circumstances without one, I would be pretty sure about 1/15 with the leica and not so sure using the same speed, fstop and film in the 7.
To be fair, that does not represent a problem to me, but as I moved to Medium Format handheld from the leica, I was pointing only what I found those days trying to use it as if it were an overgrown M6.