I think a 143 ps may have too much torque for the car. If you cam get wheel spin with a 122 ps petrol the diesel will be spinning everywhere. I know the 185 has a slip diff as standard so unless they would add that to the high power diesel.
It would definitely be a much better drive than the lower power diesels but running costs would def be higher too. Kinda the same thing as the 185 is against the 122. Be interesting to see what price it will be.