The biggest mistake for a driver to make in a Morgan 3-wheeler or similar is to assume it will handle the same as a four-wheeler, only driven a couple of copies but wouldn't even think about doing a "donut" in one.
A quad bike is great fun for razzing around but not on the road, as for trikes I agree, never understood the appeal or the point
the appeal in the UK in the 60's to some was that road tax was same as a motorbike i.e. less than a four wheeler, and it's still the same today.