The $18 solution is appealing. Is butane heavier than air?

JAXAshby wrote:

on most 20' boats, the very best is a butane chafing stove, available often
under $18 (close out store), and nearly as often for $85 (chandleries) and in
between (department stores). An okay second is an Origo 1500 non-pressurized
alcohol stove

everything else is something else, and not a hell of a lot better than a coffe
can filled with sand and some gasoline set on fire (I have cooked on such).

What are the pros and cons of these two types of stoves for a small boat
(20')?
Thanks, Grainger