I tried a bmw 335d but didn't like the way it kept hunting for gears probably due to diesels having a smaller rev range than petrols and agree the cabins are quite spartan
I have driven the 330d and at speed it's very similar, there's not a massive difference. perhaps mine pulls a bit harder at the top end but you really got to push it to find the difference.
I do like the engine characteristic, it doesn't push you back like you're in a proper sports car, i think my older EP3 Honda Type R felt quicker, the power delivery is smooth all the way through, you don't feel the kick when the bigger turbo comes into play however the rush to silly speed just keep going until it becomes a bit stupid.
F30 BMW 330d- 5.6 seconds
W212 E350 CDi 6.2 seconds
I think what is in the BMW’s favour is the superb 8 speed ZF gearbox, it’s lightening quick and you don’t really feel the changes. Probably not much in it but I feel having owned both the 330d has the edge
