Dont be fooled by climb rate numbers on the N. Usually those are with INSANE amount of fuel on board. If you think the D is a fuel tanker, check out the N... 93 gallon tank added in each wing. That is almost a 109 full fuel load EXTRA to the main tank fuel load.
The N has better roll rate than the D, larger wing area and a lot of extra power. When light on fuel it will be a monster (for 2 min... then it glides home:) ).
Down low it will not offer anything spectacular, G10, La7, P51D will still be better, but the little extra deck speed will help running away from the nimble turners. But up high... oh boy... death from above!
Bozon