A team I raced for back in the 1980s was sponsored by Nishiki. They were great bikes. Nishiki was very common in the US back then. Much like Peugot, Univega, Fuji, Centurian (now Diamond Back) and a bunch of other quality bikes.

Truthfully, the lower cost Bianchis and the Nishiki are probably built in the same Tiawanese factory. This is not a bad thing.

I suggest making your decision based on which bike fits best.