I think the originals headlights were perfect for the car, and not dated at all really. The new ones look different, but aside from being fresher to our eyes due to such newness, I don't know how the different shape, from a blank-canvas mind in a design standpoint, is fresher looking. I am shocked that the W204 might have the dual X-Mas tree LED's up front (fogs, and headlights) like the W221, while the W212 doesn't? Seems from a tech standpoint to not make sense.
I don't know how I feel about them, but aside from them, this is a perfect update. Not different enough to make anyone notice drastic changes (who aren't paying attention), so the car remains with the same character, but perfect little nuances that just keep it fresh in the market.
Now, as for the interior, this is practically a STATEMENT from M-B admitting guilt to their horrid gaffe in trying to act as if the original W204's interior is fit for even the lowest of the low from the Mercedes brand. I've never seen an interior update to extensive, for very good reason.