I've had two 240Ds (one 4 spd and one auto) and one 300D turbo. They all could be driven very hard. I make it a rule to always take it easy when cold (true of all my cars).
Around town the auto 240D was a lot of fun- easy to drive and to flogged. The 300D was terrific long distance car, especially in the mountains. Just sailed by other larger engined cars struggling to go up passes. I have logged many hours in 123 sedans and they are very reliable and confidence building cars.
I recently had a ride in a '79 240D with 79k miles on it. It was like looking at a living brochure. Everything was tight, right and nice. The car was quiet and very smooth. It is easy to see why so many people bought these cars and drove them many miles.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)