My brother and I looked at a few when he was shopping a couple months ago, test drove a 2007 E350 4-matic with 145k on it. Felt solid as a block, truly amazing car. Also drove a 2002 E320 in mint shape with 135k...also beautiful car. Ended up buying the 2002. Its been great so far, he's put over 3k on it with 0 issues, and it runs/drives fantastic. He's hooked now, I am sure he will eventually upgrade to a 2014 in a few years when you can get nice ones CPO.
We had also test driven a brand new TDI golf....and it was terrible vs. the 02 e-class, especially considering it was 2.5x the price.
Gotta say, the W210 makes the W123 seem like a horse & cart....I would describe it as a "smoother" W126 feel when driving. Its not much different from my 420 which is in mint shape, which helps a lot.
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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)