I agreed, I was telling my friend the same thing. Why is it that one of the most overrated bitches since 97 has some of the worst fanart available on the net? 49 out of 50 images of her that you come across will look like shit.
I was never familiar with the BoF series but I've seen her around alot.
Let's just say that if I were to judge both strictly by their presence on danbooru, Nina wins by far. But I suppose it has to do with the quality/quantity ratio here; Tifa's 300 pages of shit vs Nina's 4 pages of mild hits and strong misses.