I think the f83 looks better than the e93 from every angle. They both look incredibly ugly unfortunately from the side with the roof down.
I've never liked 4 seat convertible designs where all that they have done with them is shave the top off. That freshly driven under the trailer of a semi look has never appealed to me in any car. Two seat convertibles look fantastic with their tops down because they are conceived as convertibles not add-on options to something designed to be something else.
The M4's front from the side view looks like it has a bad case of cysts with its bumpy appearance. I'd say that the e93 looks better here, except that it looks even more like an ugly 80’s floating pancake design.
Now onto the good points. With the top up, from the side, the M4 looks sexy. I like the shape of the hardtop. It doesn't quite match the sexiness of its CF sister mind you, but the hardtop does give it an attractive unique look.
From the back straight on with the roof down, however, the f93 M4 looks absolutely stunning.
It looks way more menacing than the regular behinds of the M3/4.