Over the years i have owned and used these 90's, in this order:

1) Nikkor f4.5
2) Nikkor f8
3) Rodenstock Grandagon f 6.8
4) Schneider Super Angulon f8
*) And not in the same class, but a 90, the Schneider Angulon f6.8 (a tiny Dagor design).

They were all excellent, period, and you cannot go wrong form an image-quality standpoint with any of them. However, the f4.5 Nikkor and to a certain extent the Grandagon are notably heavier than the f8 versions. Since I carry my lenses in the field, my personal favorites were the lighter-weight Nikkor and Schneider f8's. I personally have settled on the Schneider SA, but only because its color/tone more closely matches my other (mostly Schneider) lenses than the Nikkor did.

Cheers,