> conversion to/from character code is easier

(1) How often do you convert from machine integers to binary character representations?

(2) If you're referring to

        for(j = 0; j < bitlen; j++) {
            bin[j] = (i & 1) ? '1': '0';
            i >>= 1;    
        }

that's the exact same for a negabinary machine.

I meant to/from numbers in text form. Usually decimal.