For me the reverse provides the most benefit when I'm shooting 2/3 sky, 1/3 land. In all other situations it replaces a hard edged filter really well.

I use hard filters all the time for WA shots, but soft is probably more versatile. I just tend to have the brightest part of my photo right by the horizon so I like to have that dark area of the filter there as well. It doesn't hurt that I live on the coast so I often have a flat horizon. Hard edged filters are also very useful for telephoto shots as soft filters become pretty ineffective once you zoom in on that transition.