Tom, that behemoth sure answers any questions about size, doesn't it?
That beast was designed to carry Soviet military payloads, but it suffered from the same design limitations as some of the smaller WIG's. The eight forward mounted engines were located that way to provide additional lift to the wings needed to overcome the problem of surface drag on takeoff - particularly in the absence of a strong oncoming wind. Once the monster was airborne, some of them could be shut down for cruising in ground effect mode. Significant power (and consequently fuel) is required to break free from the water.
The WIG/hovercraft hybrid, however, offsets this big power requirement by breaking surface friction in normal hover mode, allowing the craft to ease into ground effect flight with far less effort. That and the ability to skim up onto a ramp or a beach makes for some interesting possibilities.
Even as a pleasurecraft - can you imagine safely skimming 10 feet or so above the surface of the water or desert with a few friends at 60, 75 or 100 plus mph?