Well the C and Z buttons, are truly just digital L and R triggers. So those are what they are replacing it with I suppose. But I agree, give us C and Z buttons as well for true face buttons.
But yeah, I just hope when Retro-Bit does theirs, that they also use shoulder buttons too at least. They added them to their wireless Mega Drive/Genesis and Saturn controllers, so no reason to suspect they won't also have them on it.
Obviously, I don't think any of us hate the DC controller, we just see a few key ways it could be improved.
I know what I am doing the first day I get my wireless Retro-Bit DC controller, replacing the analog sticks like what I did with my official controllers. My latest mod turned out pretty great.