At the time, the modernisms of FFIV were a great relief. It's comfortable, and the comfort lets its quality gameplay shine through.
Arguably, FFIV's real unique factor is the fact that it forces your party layout by repeatedly and literally tossing people into the ocean. Frustrating as that can be, I can see what they were going for with that: it was meant a direct contrast to the free strategy of the FFIII job system. I just wish they didn't take their equipment with them!