On the smaller engine front, Just moved from a 1.6 diesel Volvo V40 to a 1.4 petrol (don't mention the emissions - I mentioned it once in the showroom, but I think I got away with it) Audi A3 and it is fantastic.
Diesel was sluggish at low speeds while the smaller petrol is much more nimble, and as fast as you need on A roads and motorways.
Engine is so quiet, can't tell when its on at lower revs.
The game has moved on. Don't think I will be moving back to diesel, at least on smaller cars.
You know it makes sense! 
