Post History

* MOV are bidirectional components suitable for both AC and DC circuits, TVS are most often unidirectional, despite bidirectional TVS are also available;
* conducts more current compared to TVS diodes (in general);
* dissipates energy in a solid material and not in a junction.

I would use a MOV where I need to dissipate a lot of power. But that's just a declaration of principle. The detailed answer of Olin is the right way.