I have had 4 different SDEs, called SD1 down here and better built, with stronger rear suspension and no self leveling, which seemed to have been the right decision, as the Boge Niveaumat proved to be troublesome.
I enjoyed each of the 500000km i did in mine, but they were all V8s.
We also had a 2600, with an Australian engine, that was further "modified" here. That thing was gutless and had few redeeming features, often cracked the exhaust manifold.
I have never seen the lesser models in the UK, but I would be surprised if the 2300 was not even more lifeless than our 2600.
All in all a very good car, let down by a drab interior in the early models. Talking about brown, brown and even more brown! Truly depressing.
Apart from that a car I hold in high esteem, and far underrated by people that did not know them. The UK build quality was also shocking at times.
I still have three of mine, hoping against hope to rebuild one one day!
I doubt it will ever happen!