It was only barely comparable with planes already in construction at the time. The -N was a last-ditch effort to keep the P-40 competitive, and it failed.
Now, I guess I wouldn't MIND seeing it, but I don't think we need it or have a gap it would fill.
The P40N does have 6 guns (some only had 4, if I recall to save weight) but the rounds per guns were much less than any other plane. It had about 260 or 250. Whatever the E has, I believe it has the same.
Compare this to 375rpg in naval planes, and 400rpg in later naval planes and later USAAF planes. It was too little too late.
That aside, like I said I wouldn't mind seeing it but I'd hate to have it instead of a mig3 or a yak1 or a (fill in the blank). If there was something more pressing I'd rather have that instead.