If there is no real time playback... the whole thing is kind of useless for TV spot production work.
I hear people say, that shooting raw is expensive and they count the dollar per minute cost, but I would buy most expensive cards on the planet and have my money back in a couple of days of shooting, because instead of renting Red Epic (600$ per shift) or Alexa(1000$ per shift),paying camera technition (200$ per shift) and SDI field monitor (60$ per shift) I just bring my raw 5d, shoot the commercial and go back home to make family pictures and videos with the same tool. Of course there is a BIG risk to shoot the commissioned work on the hacked 5d, so I would test it couple of month in a different conditions before I ever take it to any serious shoot.
I really hope the ML team will get it to the point when it is reliable and solid. For now 5d's H264 and Pro cameras are the save option. Although I would never rent or buy any of canon's C line cameras, just because I don't want to give any profit to the gritty bstrds canon.