I prefer the look of the coupe. and since the coupe is pillarless anyways, i bet this took minimal engineering.
as for the look being overused, maybe. But MB has a family look that is stronger than any other brand, even BMW at this point. Over the past few years the styling has been nothing short of brilliant on every MB car, except the A-Class and the rear of the C-Coupe. And well the G500 doesnt count. You get my point though.
As for no folding hardtop, I think theyll want to leave that for the more expensive CL covritble that is rumored to come. I mean, if this had one there wouldnt be much reason to spend the extra 30k or whatever for the CL.