IIRC Autoexpress tested this years version (now called 4D I think) and gave it top marks but it was a pre production model so didnt actually put it in the top 3. So in summary – a 3D will be better than fine!
As for 2 vs 4 debate – I’ve done 2 winters with 2 on the front (fwd) and as we live on a slight hill (but regular visits at inlaws on a steep hill) the sideways excitement just got too much: always braking, coming back down the hill and we now put 4 on at least one car.
You can live with 2. And get going. Stopping is more entertaining esp on a hill for some reason.
With a RWD you defo need all 4. A non braking non steering 5 series is not something I’d risk others lives with again.