Things I miss from W211 vs W212 `
 

Coming out of a 2005 CDI in to a new E 250. There are some things I miss and things I do not miss

Miss the headlamp washers, Did not use too often but liked them when I did

Miss, Rear headrest auto knockdown. Never used it other than showing people how cool it was. I guess MB had the same thought

Miss, Heated window washer nozzles. Maybe the W212 has them not sure was a nice feature

Miss, Air intake on the hood. The old school grill on the hood for cabin air was just cool.

Miss, Dual dynamic seats. Now just the driver side has them if optioned

Miss, Rear seat shades. Can get them but purchased the W212 from inventory

Miss, The clock automatically changing when you cross in to a new time zone.

Don't miss the fear of the SBC brake system failure. My 2005 went 225,000 miles no issues but it always concerned me.

Kind of miss, The old I 6 cyl cast iron diesel sound, Trucker like at idle

Miss, Spare tire, run flats ride terrible

in addition

Miss, battery on my 05 CDI was original at 225K miles, never one issue in the cold of Chicago

It's really heat that kills batteries, cold actually makes it last longer. But AGM batteries lasting 8-10 years is normal. On the W212, they had headlamp washers on the 2010-2013 when they had Bixenons available as an option, but once they went to LED in 2014+, they got rid of the headlamp washers.

The Bixenons were nice but they faded over time. Specially as DRL. Full LED is really nice on the new W212. Expect the LED's will last forever.
No other bulb ever burned out on my W211.

Like all bulbs, they will fade over time. Even the LEDs, but their life span is greater so by the time it fades, it will be long gone.

MISS: Seeing Manufactured by Daimler-Chrysler on the B pillar of my W212, NOT!!!!

I have a w212 2014 E550 and have 2 of those items you mentioned.
rear kick down head rests
spare tire

Do your seats fold down om the E550?

Miss the small starage drawer on W211, not too useful though just for coins
The CD changer door on the W211 was cool too

My seats don't fold down its a option though. I have a small storage area at the front of the driver seat which is nice. I have not been in a W211 though so not sure whats different in general. I have had a car with washing headlights though and imo it just makes a mess especially on a black car. I just got my E550 this week though but have had ml's for a few years so learning new stuff everyday. I wish the Eclass had folding mirrors.

my new E has folding mirrors. My old E and new have the storage in front of drivers and passenger seat. I Europe a fire extinguisher goes in one of these. I tend to agree on the mess the washers would make. I mostly used in the chicago winter to blast the salt and sludge off in bad weather