Every chemistry should work in a very, very similar way. If it does not, then it fails miserably and shouldn't be sold at all. If you get good results, that just means that the chemistry is at least usable. That's all. If you want to compare, you have to do very careful side-by-side comparisons with the exactly same images on the same film and with very careful processing. Then, there is probably very little difference in any chemistries.

It would be interesting, though, to see a proper comparison about the promised possibility to process in different temperatures than 37.8C, to see if Fuji/Kodak chemicals work as well with the same temps/times or not.

Superia 1600 is very fine-grained. 30x20 cm optical prints show very manageable grain. I don't find it especially contrasty, either.