Jokes aside, it is my most humble opinion that the original prototype is the way to go. The name itself stands for it: DAN A4 (with h20) and it should be totally recognisable at first glance by that concept.
"Hey, that's an A4! no, wait..." That was my first thought when I watched the Optimum preview and the product should go after that. Yes, it is good to innovate, it is refreshing somehow but there is a C4 coming in, with a totally unique design and features that will make it itself, the same way that the rounded front panel, button placement and some other subtle details make the A4 what it is.
Again, this is only my two cents on the topic and I mean no harm to the project and Dan awesome work!